diff --git a/TODO.md b/TODO.md
index 3961a35..d24ff87 100644
--- a/TODO.md
+++ b/TODO.md
@@ -102,7 +102,6 @@ Common UI
 Technical
 ---------
 
-* Remove references from battle internals (ships, fleets...) to universe (it causes large serialized battles in campaign mode)
 * Pack all images in atlases, and split them by stage
 * Pack sounds
 * Add toggles for shaders, automatically disable them if too slow, and initially disable them on mobile
diff --git a/src/core/Battle.spec.ts b/src/core/Battle.spec.ts
index ee04ad7..4d06895 100644
--- a/src/core/Battle.spec.ts
+++ b/src/core/Battle.spec.ts
@@ -269,7 +269,7 @@ module TK.SpaceTac {
 
             check.equals(battle.canPlay(player), false);
 
-            ship.fleet.player = player;
+            ship.fleet.setPlayer(player);
 
             check.equals(battle.canPlay(player), true);
         });
@@ -358,9 +358,19 @@ module TK.SpaceTac {
 
             let loaded = serializer.unserialize(data);
 
-            check.equals(loaded.ai_playing, false);
+            check.equals(loaded.ai_playing, false, "ai playing is reset");
             battle.ai_playing = false;
-            check.equals(loaded, battle);
+            check.equals(loaded, battle, "unserialized == initial");
+
+            let session = new GameSession();
+            session.startNewGame();
+            session.start_location.setupEncounter();
+            session.start_location.enterLocation(session.player.fleet);
+            let battle1 = nn(session.getBattle());
+            let data1 = serializer.serialize(battle1);
+
+            let ratio = data.length / data1.length;
+            check.greaterorequal(ratio, 1.2, `quick battle serialized size (${data.length}) should be larger than campaign's (${data1.length})`);
         });
 
         test.case("can revert the last action", check => {
diff --git a/src/core/Battle.ts b/src/core/Battle.ts
index 322f8a2..fcc1ad7 100644
--- a/src/core/Battle.ts
+++ b/src/core/Battle.ts
@@ -6,9 +6,6 @@ module TK.SpaceTac {
         // Battle outcome, if the battle has ended
         outcome: BattleOutcome | null = null
 
-        // Battle cheats
-        cheats: BattleCheats
-
         // Statistics
         stats: BattleStats
 
@@ -43,7 +40,7 @@ module TK.SpaceTac {
         // Indicator that an AI is playing
         ai_playing = false
 
-        constructor(fleet1 = new Fleet(new Player(undefined, "Attacker")), fleet2 = new Fleet(new Player(undefined, "Defender")), width = 1808, height = 948) {
+        constructor(fleet1 = new Fleet(new Player("Attacker")), fleet2 = new Fleet(new Player("Defender")), width = 1808, height = 948) {
             this.fleets = [fleet1, fleet2];
             this.ships = new RObjectContainer(fleet1.ships.concat(fleet2.ships));
             this.play_order = [];
@@ -52,7 +49,6 @@ module TK.SpaceTac {
 
             this.log = new BattleLog();
             this.stats = new BattleStats();
-            this.cheats = new BattleCheats(this, fleet1.player);
 
             this.fleets.forEach((fleet: Fleet) => {
                 fleet.setBattle(this);
@@ -123,23 +119,26 @@ module TK.SpaceTac {
         /**
          * Return an iterator over ships allies of (or owned by) a player
          */
-        iallies(player: Player, alive_only = false): Iterator<Ship> {
-            return ifilter(this.iships(alive_only), ship => ship.getPlayer() === player);
+        iallies(ship: Ship, alive_only = false): Iterator<Ship> {
+            return ifilter(this.iships(alive_only), iship => iship.fleet.player.is(ship.fleet.player));
         }
 
         /**
          * Return an iterator over ships enemy of a player
          */
-        ienemies(player: Player, alive_only = false): Iterator<Ship> {
-            return ifilter(this.iships(alive_only), ship => ship.getPlayer() !== player);
+        ienemies(ship: Ship, alive_only = false): Iterator<Ship> {
+            return ifilter(this.iships(alive_only), iship => !iship.fleet.player.is(ship.fleet.player));
         }
 
-        // Check if a player is able to play
-        //  This can be used by the UI to determine if player interaction is allowed
+        /**
+         * Check if a player is able to play
+         * 
+         * This can be used by the UI to determine if player interaction is allowed
+         */
         canPlay(player: Player): boolean {
             if (this.ended) {
                 return false;
-            } else if (this.playing_ship && this.playing_ship.getPlayer() == player) {
+            } else if (this.playing_ship && player.is(this.playing_ship.fleet.player)) {
                 return this.playing_ship.isAbleToPlay(false);
             } else {
                 return false;
diff --git a/src/core/BattleCheats.spec.ts b/src/core/BattleCheats.spec.ts
index bf4e7c4..8e99910 100644
--- a/src/core/BattleCheats.spec.ts
+++ b/src/core/BattleCheats.spec.ts
@@ -2,8 +2,10 @@ module TK.SpaceTac.Specs {
     testing("BattleCheats", test => {
         test.case("wins a battle", check => {
             let battle = Battle.newQuickRandom();
+            let cheats = new BattleCheats(battle, battle.fleets[0].player);
+
+            cheats.win();
 
-            battle.cheats.win();
             check.equals(battle.ended, true, "ended");
             check.same(nn(battle.outcome).winner, battle.fleets[0], "winner");
             check.equals(any(battle.fleets[1].ships, ship => ship.alive), false, "all enemies dead");
@@ -11,8 +13,10 @@ module TK.SpaceTac.Specs {
 
         test.case("loses a battle", check => {
             let battle = Battle.newQuickRandom();
+            let cheats = new BattleCheats(battle, battle.fleets[0].player);
+
+            cheats.lose();
 
-            battle.cheats.lose();
             check.equals(battle.ended, true, "ended");
             check.same(nn(battle.outcome).winner, battle.fleets[1], "winner");
             check.equals(any(battle.fleets[0].ships, ship => ship.alive), false, "all allies dead");
@@ -23,9 +27,12 @@ module TK.SpaceTac.Specs {
             let ship = new Ship();
             TestTools.setShipPlaying(battle, ship);
             ship.upgradeSkill("skill_materials");
+            let cheats = new BattleCheats(battle, battle.fleets[0].player);
 
             check.equals(ship.listEquipment(), []);
-            battle.cheats.equip("Iron Hull");
+
+            cheats.equip("Iron Hull");
+
             let result = ship.listEquipment();
             check.equals(result.length, 1);
             check.containing(result[0], { name: "Iron Hull", level: 1 });
diff --git a/src/core/BattleCheats.ts b/src/core/BattleCheats.ts
index f4ca3f4..dd50c7c 100644
--- a/src/core/BattleCheats.ts
+++ b/src/core/BattleCheats.ts
@@ -18,7 +18,7 @@ module TK.SpaceTac {
          */
         win(): void {
             iforeach(this.battle.iships(), ship => {
-                if (ship.fleet.player != this.player) {
+                if (!this.player.is(ship.fleet.player)) {
                     ship.setDead();
                 }
             });
@@ -30,11 +30,11 @@ module TK.SpaceTac {
          */
         lose(): void {
             iforeach(this.battle.iships(), ship => {
-                if (ship.fleet.player == this.player) {
+                if (this.player.is(ship.fleet.player)) {
                     ship.setDead();
                 }
             });
-            this.battle.endBattle(first(this.battle.fleets, fleet => fleet.player != this.player));
+            this.battle.endBattle(first(this.battle.fleets, fleet => !this.player.is(fleet.player)));
         }
 
         /**
diff --git a/src/core/BattleOutcome.ts b/src/core/BattleOutcome.ts
index 2acdff9..7fbbcb2 100644
--- a/src/core/BattleOutcome.ts
+++ b/src/core/BattleOutcome.ts
@@ -27,7 +27,7 @@ module TK.SpaceTac {
             this.loot = [];
 
             battle.fleets.forEach(fleet => {
-                if (this.winner && this.winner.player != fleet.player) {
+                if (this.winner && !this.winner.player.is(fleet.player)) {
                     fleet.ships.forEach(ship => {
                         var luck = random.random();
                         if (luck > 0.9) {
diff --git a/src/core/Fleet.spec.ts b/src/core/Fleet.spec.ts
index 8f20d5c..0b51652 100644
--- a/src/core/Fleet.spec.ts
+++ b/src/core/Fleet.spec.ts
@@ -49,37 +49,92 @@ module TK.SpaceTac {
 
         test.case("changes location, only using jumps to travel between systems", check => {
             let fleet = new Fleet();
-            let system1 = new Star();
-            let system2 = new Star();
-            let jump1 = new StarLocation(system1, StarLocationType.WARP);
-            let jump2 = new StarLocation(system2, StarLocationType.WARP);
+            let universe = new Universe();
+            let system1 = universe.addStar();
+            let system2 = universe.addStar();
+            let jump1 = system1.addLocation(StarLocationType.WARP);
+            let jump2 = system2.addLocation(StarLocationType.WARP);
             jump1.setJumpDestination(jump2);
             jump2.setJumpDestination(jump1);
-            let other1 = new StarLocation(system1, StarLocationType.PLANET);
+            let other1 = system1.addLocation(StarLocationType.PLANET);
+            universe.updateLocations();
 
-            let result = fleet.setLocation(other1);
-            check.equals(result, true);
-            check.same(fleet.location, other1);
+            let result = fleet.move(other1);
+            check.in("cannot move from nowhere", check => {
+                check.equals(result, false);
+                check.equals(fleet.location, null);
+            });
 
-            result = fleet.setLocation(jump2);
-            check.equals(result, false);
-            check.same(fleet.location, other1);
+            fleet.setLocation(other1);
+            check.in("force set to other1", check => {
+                check.equals(fleet.location, other1.id);
+            });
 
-            result = fleet.setLocation(jump1);
-            check.equals(result, true);
-            check.same(fleet.location, jump1);
+            result = fleet.move(jump2);
+            check.in("other1=>jump2", check => {
+                check.equals(result, false);
+                check.equals(fleet.location, other1.id);
+            });
 
-            result = fleet.setLocation(jump2);
-            check.equals(result, true);
-            check.same(fleet.location, jump2);
+            result = fleet.move(jump1);
+            check.in("other1=>jump1", check => {
+                check.equals(result, true);
+                check.equals(fleet.location, jump1.id);
+            });
 
-            result = fleet.setLocation(other1);
-            check.equals(result, false);
-            check.same(fleet.location, jump2);
+            result = fleet.move(jump2);
+            check.in("jump1=>jump2", check => {
+                check.equals(result, true);
+                check.equals(fleet.location, jump2.id);
+            });
 
-            result = fleet.setLocation(jump1);
-            check.equals(result, true);
-            check.same(fleet.location, jump1);
+            result = fleet.move(other1);
+            check.in("jump2=>other1", check => {
+                check.equals(result, false);
+                check.equals(fleet.location, jump2.id);
+            });
+
+            result = fleet.move(jump1);
+            check.in("jump2=>jump1", check => {
+                check.equals(result, true);
+                check.equals(fleet.location, jump1.id);
+            });
+        });
+
+        test.case("registers presence in locations, and keeps track of visited locations", check => {
+            let fleet = new Fleet();
+            let universe = new Universe();
+            let star = universe.addStar();
+            let loc1 = star.addLocation(StarLocationType.PLANET);
+            let loc2 = star.addLocation(StarLocationType.PLANET);
+            let loc3 = star.addLocation(StarLocationType.PLANET);
+            universe.updateLocations();
+
+            function checks(desc: string, fleets1: Fleet[], fleets2: Fleet[], fleets3: Fleet[], visited: RObjectId[]) {
+                check.in(desc, check => {
+                    check.equals(loc1.fleets, fleets1, "loc1 fleets");
+                    check.equals(loc2.fleets, fleets2, "loc2 fleets");
+                    check.equals(loc3.fleets, fleets3, "loc3 fleets");
+                    check.equals(fleet.visited, visited, "visited");
+                });
+            }
+
+            checks("initial", [], [], [], []);
+
+            fleet.setLocation(loc1);
+            checks("first move to loc1", [fleet], [], [], [loc1.id]);
+
+            fleet.setLocation(loc1);
+            checks("already in loc1", [fleet], [], [], [loc1.id]);
+
+            fleet.setLocation(loc2);
+            checks("first move to loc2", [], [fleet], [], [loc2.id, loc1.id]);
+
+            fleet.setLocation(loc3);
+            checks("first move to loc3", [], [], [fleet], [loc3.id, loc2.id, loc1.id]);
+
+            fleet.setLocation(loc2);
+            checks("go back to loc2", [], [fleet], [], [loc2.id, loc3.id, loc1.id]);
         });
 
         test.case("checks if a fleet is alive", check => {
diff --git a/src/core/Fleet.ts b/src/core/Fleet.ts
index 961b6c5..1c0281c 100644
--- a/src/core/Fleet.ts
+++ b/src/core/Fleet.ts
@@ -4,58 +4,98 @@ module TK.SpaceTac {
      */
     export class Fleet {
         // Fleet owner
-        player: Player;
+        player: Player
+
+        // Fleet name
+        name: string
 
         // List of ships
-        ships: Ship[];
+        ships: Ship[]
 
         // Current fleet location
-        location: StarLocation | null = null;
-        previous_location: StarLocation | null = null;
+        location: RObjectId | null = null
+
+        // Visited locations (ordered by last visited)
+        visited: RObjectId[] = []
 
         // Current battle in which the fleet is engaged (null if not fighting)
-        battle: Battle | null = null;
+        battle: Battle | null = null
 
         // Amount of credits available
-        credits = 0;
+        credits = 0
 
         // Create a fleet, bound to a player
         constructor(player = new Player()) {
             this.player = player;
+            this.name = player ? player.name : "Fleet";
             this.ships = [];
         }
 
         jasmineToString(): string {
-            return `${this.player.name}'s fleet [${this.ships.map(ship => ship.getName()).join(",")}]`;
+            return `${this.name} [${this.ships.map(ship => ship.getName()).join(",")}]`;
         }
 
         /**
-         * Set the current location of the fleet
+         * Set the owner player
+         */
+        setPlayer(player: Player): void {
+            this.player = player;
+        }
+
+        /**
+         * Set a location as visited
+         */
+        setVisited(location: StarLocation): void {
+            remove(this.visited, location.id);
+            this.visited.unshift(location.id);
+        }
+
+        /**
+         * Move the fleet to another location, checking that the move is physically possible
          * 
          * Returns true on success
          */
-        setLocation(location: StarLocation, force = false): boolean {
-            if (!force && this.location && location.star != this.location.star && (this.location.type != StarLocationType.WARP || this.location.jump_dest != location)) {
+        move(to: StarLocation): boolean {
+            if (!this.location) {
                 return false;
             }
 
-            this.previous_location = this.location;
-            this.location = location;
-            this.player.setVisited(this.location);
-
-            // Check encounter
-            var battle = this.location.enterLocation(this.player.fleet);
-            if (battle) {
-                this.player.setBattle(battle);
+            let source = to.universe.locations.get(this.location);
+            if (!source) {
+                return false;
             }
 
+            if (source.star != to.star) {
+                // Need to jump, check conditions
+                if (source.type != StarLocationType.WARP || source.jump_dest != to) {
+                    return false;
+                }
+            }
+
+            this.setLocation(to);
             return true;
         }
 
+        /**
+         * Set the current location of the fleet, without condition
+         */
+        setLocation(location: StarLocation): void {
+            if (this.location) {
+                let previous = location.universe.locations.get(this.location);
+                if (previous) {
+                    previous.removeFleet(this);
+                }
+            }
+
+            this.location = location.id;
+            this.setVisited(location);
+            location.addFleet(this);
+        }
+
         /**
          * Add a ship this fleet
          */
-        addShip(ship = new Ship(null, `${this.player.name} ${this.ships.length + 1}`)): Ship {
+        addShip(ship = new Ship(null, `${this.name} ${this.ships.length + 1}`)): Ship {
             if (ship.fleet && ship.fleet != this) {
                 remove(ship.fleet.ships, ship);
             }
diff --git a/src/core/GameSession.spec.ts b/src/core/GameSession.spec.ts
index b4ffdd2..0ad1b7b 100644
--- a/src/core/GameSession.spec.ts
+++ b/src/core/GameSession.spec.ts
@@ -40,8 +40,11 @@ module TK.SpaceTac.Specs {
             let session = new GameSession();
             check.equals(session.getBattle(), null);
 
-            // Victory case
             let location1 = new StarLocation();
+            let location2 = new StarLocation(location1.star);
+            session.universe.locations = new RObjectContainer([location1, location2]);
+
+            // Victory case
             location1.encounter = new Fleet();
             session.player.fleet.setLocation(location1);
             check.notequals(session.getBattle(), null);
@@ -56,7 +59,6 @@ module TK.SpaceTac.Specs {
             check.called(spyloot, 1);
 
             // Defeat case
-            let location2 = new StarLocation(location1.star);
             location2.encounter = new Fleet();
             session.player.fleet.setLocation(location2);
             check.notequals(session.getBattle(), null);
@@ -78,7 +80,7 @@ module TK.SpaceTac.Specs {
             check.notequals(session.player, null);
             check.equals(session.player.fleet.ships.length, 0);
             check.equals(session.player.fleet.credits, 0);
-            check.equals(session.player.universe.stars.length, 50);
+            check.equals(session.universe.stars.length, 50);
             check.equals(session.getBattle(), null);
             check.equals(session.start_location.shop, null);
             check.equals(session.start_location.encounter, null);
@@ -87,7 +89,47 @@ module TK.SpaceTac.Specs {
             session.setCampaignFleet();
             check.equals(session.player.fleet.ships.length, 2);
             check.equals(session.player.fleet.credits, 0);
-            check.same(session.player.fleet.location, session.start_location);
+            check.equals(session.player.fleet.location, session.start_location.id);
+        });
+
+        test.case("can revert battle", check => {
+            let session = new GameSession();
+            let star = session.universe.addStar();
+            let loc1 = star.addLocation(StarLocationType.PLANET);
+            loc1.clearEncounter();
+            let loc2 = star.addLocation(StarLocationType.PLANET);
+            loc2.encounter_random = new SkewedRandomGenerator([0], true);
+            session.universe.updateLocations();
+
+            session.fleet.setLocation(loc1);
+            check.in("init in loc1", check => {
+                check.equals(session.getBattle(), null, "bound battle");
+                check.equals(session.fleet.location, loc1.id, "fleet location");
+                check.equals(session.player.hasVisitedLocation(loc2), false, "visited");
+            });
+
+            session.fleet.setLocation(loc2);
+            check.in("move to loc2", check => {
+                check.notequals(session.getBattle(), null, "bound battle");
+                check.equals(session.fleet.location, loc2.id, "fleet location");
+                check.equals(session.player.hasVisitedLocation(loc2), true, "visited");
+            });
+            let enemy = loc2.encounter;
+
+            session.revertBattle();
+            check.in("reverted", check => {
+                check.equals(session.getBattle(), null, "bound battle");
+                check.equals(session.fleet.location, loc1.id, "fleet location");
+                check.equals(session.player.hasVisitedLocation(loc2), true, "visited");
+            });
+
+            session.fleet.setLocation(loc2);
+            check.in("move to loc2 again", check => {
+                check.notequals(session.getBattle(), null, "bound battle");
+                check.equals(session.fleet.location, loc2.id, "fleet location");
+                check.equals(session.player.hasVisitedLocation(loc2), true, "visited");
+                check.same(nn(session.getBattle()).fleets[1], nn(enemy), "same enemy");
+            });
         });
 
         /*test.case("can generate lots of new games", check => {
diff --git a/src/core/GameSession.ts b/src/core/GameSession.ts
index 9b8f070..a8e86be 100644
--- a/src/core/GameSession.ts
+++ b/src/core/GameSession.ts
@@ -32,11 +32,18 @@ module TK.SpaceTac {
         constructor() {
             this.id = RandomGenerator.global.id(20);
             this.universe = new Universe();
-            this.player = new Player(this.universe);
+            this.player = new Player();
             this.reactions = new PersonalityReactions();
             this.start_location = new StarLocation();
         }
 
+        /**
+         * Get the currently played fleet
+         */
+        get fleet(): Fleet {
+            return this.player.fleet;
+        }
+
         /**
          * Get an indicative description of the session (to help identify game saves)
          */
@@ -71,7 +78,7 @@ module TK.SpaceTac {
             this.start_location.clearEncounter();
             this.start_location.removeShop();
 
-            this.player = new Player(this.universe);
+            this.player = new Player();
 
             this.reactions = new PersonalityReactions();
 
@@ -88,34 +95,52 @@ module TK.SpaceTac {
         setCampaignFleet(fleet: Fleet | null = null, story = true) {
             if (fleet) {
                 this.player.fleet = fleet;
-                fleet.player = this.player;
+                fleet.setPlayer(this.player);
             } else {
                 let fleet_generator = new FleetGenerator();
                 this.player.fleet = fleet_generator.generate(1, this.player, 2);
             }
 
-            this.player.fleet.setLocation(this.start_location, true);
+            this.player.fleet.setLocation(this.start_location);
 
             if (story) {
                 this.player.missions.startMainStory(this.universe, this.player.fleet);
             }
         }
 
-        // Start a new "quick battle" game
+        /**
+         * Start a new "quick battle" game
+         */
         startQuickBattle(with_ai: boolean = false): void {
+            this.universe = new Universe();
+
             let battle = Battle.newQuickRandom(true, RandomGenerator.global.randInt(1, 10));
-            this.player = battle.fleets[0].player;
+            battle.fleets[0].setPlayer(this.player);
             this.player.setBattle(battle);
+
             this.reactions = new PersonalityReactions();
         }
 
-        // Get currently played battle, null when none is in progress
+        /**
+         * Get currently played battle, null when none is in progress
+         */
         getBattle(): Battle | null {
             return this.player.getBattle();
         }
 
         /**
-         * Set the end of current battle
+         * Get the main fleet's location
+         */
+        getLocation(): StarLocation {
+            return this.universe.getLocation(this.player.fleet.location) || new StarLocation();
+        }
+
+        /**
+         * Set the end of current battle.
+         * 
+         * This will reset the fleet, grant experience, and create loot.
+         * 
+         * The battle will still be bound to the session (exitBattle or revertBattle should be called after).
          */
         setBattleEnded() {
             let battle = this.getBattle();
@@ -133,13 +158,34 @@ module TK.SpaceTac {
                 }
 
                 // If the battle happened in a star location, keep it informed
-                let location = this.player.fleet.location;
+                let location = this.universe.getLocation(this.player.fleet.location);
                 if (location) {
                     location.resolveEncounter(battle.outcome);
                 }
             }
         }
 
+        /**
+         * Exit the current battle unconditionally, if any
+         * 
+         * This does not apply retreat penalties, or battle outcome, only unbind the battle from current session
+         */
+        exitBattle(): void {
+            this.player.setBattle(null);
+        }
+
+        /**
+         * Revert current battle, and put the player's fleet to its previous location, as if the battle never happened
+         */
+        revertBattle(): void {
+            this.exitBattle();
+
+            let previous_location = this.universe.getLocation(this.fleet.visited[1]);
+            if (previous_location) {
+                this.fleet.setLocation(previous_location);
+            }
+        }
+
         /**
          * Returns true if the session has an universe to explore (campaign mode)
          */
diff --git a/src/core/PersonalityReactions.spec.ts b/src/core/PersonalityReactions.spec.ts
index f108acd..e7f049b 100644
--- a/src/core/PersonalityReactions.spec.ts
+++ b/src/core/PersonalityReactions.spec.ts
@@ -51,15 +51,17 @@ module TK.SpaceTac.Specs {
         test.case("checks for friendly fire", check => {
             let condition = BUILTIN_REACTION_POOL['friendly_fire'][0];
             let battle = new Battle();
+            let player = new Player();
+            battle.fleets[0].setPlayer(player);
             let ship1a = battle.fleets[0].addShip();
             let ship1b = battle.fleets[0].addShip();
             let ship2a = battle.fleets[1].addShip();
             let ship2b = battle.fleets[1].addShip();
 
-            check.equals(condition(ship1a.getPlayer(), battle, ship1a, new ShipDamageDiff(ship1a, 50, 10)), [], "self shoot");
-            check.equals(condition(ship1a.getPlayer(), battle, ship1a, new ShipDamageDiff(ship1b, 50, 10)), [ship1b, ship1a]);
-            check.equals(condition(ship1a.getPlayer(), battle, ship1a, new ShipDamageDiff(ship2a, 50, 10)), [], "enemy shoot");
-            check.equals(condition(ship1a.getPlayer(), battle, ship2a, new ShipDamageDiff(ship2a, 50, 10)), [], "other player event");
+            check.equals(condition(player, battle, ship1a, new ShipDamageDiff(ship1a, 50, 10)), [], "self shoot");
+            check.equals(condition(player, battle, ship1a, new ShipDamageDiff(ship1b, 50, 10)), [ship1b, ship1a]);
+            check.equals(condition(player, battle, ship1a, new ShipDamageDiff(ship2a, 50, 10)), [], "enemy shoot");
+            check.equals(condition(player, battle, ship2a, new ShipDamageDiff(ship2a, 50, 10)), [], "other player event");
         })
     })
 }
diff --git a/src/core/PersonalityReactions.ts b/src/core/PersonalityReactions.ts
index 2654221..d260310 100644
--- a/src/core/PersonalityReactions.ts
+++ b/src/core/PersonalityReactions.ts
@@ -93,9 +93,9 @@ module TK.SpaceTac {
      */
     function cond_friendly_fire(player: Player, battle: Battle | null, ship: Ship | null, event: BaseBattleDiff | null): Ship[] {
         if (battle && ship && event) {
-            if (event instanceof ShipDamageDiff && player.is(ship.getPlayer()) && !ship.is(event.ship_id)) {
+            if (event instanceof ShipDamageDiff && player.is(ship.fleet.player) && !ship.is(event.ship_id)) {
                 let hurt = battle.getShip(event.ship_id);
-                return (hurt && hurt.getPlayer().is(player)) ? [hurt, ship] : [];
+                return (hurt && player.is(hurt.fleet.player)) ? [hurt, ship] : [];
             } else {
                 return [];
             }
diff --git a/src/core/Player.spec.ts b/src/core/Player.spec.ts
index 4456410..7ebd5c2 100644
--- a/src/core/Player.spec.ts
+++ b/src/core/Player.spec.ts
@@ -2,12 +2,14 @@ module TK.SpaceTac {
     testing("Player", test => {
         test.case("keeps track of visited locations", check => {
             let player = new Player();
-            let star1 = new Star();
-            let star2 = new Star();
-            let loc1a = new StarLocation(star1);
-            let loc1b = new StarLocation(star1);
-            let loc2a = new StarLocation(star2);
-            let loc2b = new StarLocation(star2);
+            let universe = new Universe();
+            let star1 = universe.addStar();
+            let star2 = universe.addStar();
+            let loc1a = star1.addLocation(StarLocationType.PLANET);
+            let loc1b = star1.addLocation(StarLocationType.PLANET);
+            let loc2a = star2.addLocation(StarLocationType.PLANET);
+            let loc2b = star2.addLocation(StarLocationType.PLANET);
+            universe.updateLocations();
 
             function checkVisited(s1 = false, s2 = false, v1a = false, v1b = false, v2a = false, v2b = false) {
                 check.same(player.hasVisitedSystem(star1), s1);
@@ -20,51 +22,17 @@ module TK.SpaceTac {
 
             checkVisited();
 
-            player.setVisited(loc1b);
-
+            player.fleet.setLocation(loc1b);
             checkVisited(true, false, false, true, false, false);
 
-            player.setVisited(loc1a);
-
+            player.fleet.setLocation(loc1a);
             checkVisited(true, false, true, true, false, false);
 
-            player.setVisited(loc2a);
-
+            player.fleet.setLocation(loc2a);
             checkVisited(true, true, true, true, true, false);
 
-            player.setVisited(loc2a);
-
+            player.fleet.setLocation(loc2a);
             checkVisited(true, true, true, true, true, false);
         });
-
-        test.case("reverts battle", check => {
-            let player = new Player();
-            let star = new Star();
-            let loc1 = new StarLocation(star);
-            loc1.clearEncounter();
-            let loc2 = new StarLocation(star);
-            loc2.encounter_random = new SkewedRandomGenerator([0], true);
-
-            player.fleet.setLocation(loc1);
-            check.equals(player.getBattle(), null);
-            check.same(player.fleet.location, loc1);
-
-            player.fleet.setLocation(loc2);
-            check.notequals(player.getBattle(), null);
-            check.same(player.fleet.location, loc2);
-            check.equals(player.hasVisitedLocation(loc2), true);
-            let enemy = loc2.encounter;
-
-            player.revertBattle();
-            check.equals(player.getBattle(), null);
-            check.same(player.fleet.location, loc1);
-            check.equals(player.hasVisitedLocation(loc2), true);
-
-            player.fleet.setLocation(loc2);
-            check.notequals(player.getBattle(), null);
-            check.same(player.fleet.location, loc2);
-            check.equals(player.hasVisitedLocation(loc2), true);
-            check.same(nn(player.getBattle()).fleets[1], nn(enemy));
-        });
     });
 }
\ No newline at end of file
diff --git a/src/core/Player.ts b/src/core/Player.ts
index cc27735..ba3906b 100644
--- a/src/core/Player.ts
+++ b/src/core/Player.ts
@@ -8,57 +8,54 @@ module TK.SpaceTac {
         // Player's name
         name: string
 
-        // Universe in which we are playing
-        universe: Universe
-
-        // Current fleet
+        // Bound fleet
         fleet: Fleet
 
-        // List of visited star systems
-        visited: StarLocation[] = []
-
         // Active missions
         missions = new ActiveMissions()
 
         // Create a player, with an empty fleet
-        constructor(universe: Universe = new Universe(), name = "Player") {
+        constructor(name = "Player", fleet?: Fleet) {
             super();
 
-            this.universe = universe;
             this.name = name;
-            this.fleet = new Fleet(this);
+            this.fleet = fleet || new Fleet(this);
+
+            this.fleet.setPlayer(this);
         }
 
         // Create a quick random player, with a fleet, for testing purposes
         static newQuickRandom(name: string, level = 1, shipcount = 4, upgrade = false): Player {
-            let player = new Player(new Universe(), name);
+            let player = new Player(name);
             let generator = new FleetGenerator();
             player.fleet = generator.generate(level, player, shipcount, upgrade);
             return player;
         }
 
+        /**
+         * Get a cheats object
+         */
+        getCheats(): BattleCheats | null {
+            let battle = this.getBattle();
+            if (battle) {
+                return new BattleCheats(battle, this);
+            } else {
+                return null;
+            }
+        }
+
         /**
          * Return true if the player has visited at least one location in a given system.
          */
         hasVisitedSystem(system: Star): boolean {
-            return any(this.visited, location => location.star == system);
+            return intersection(this.fleet.visited, system.locations.map(loc => loc.id)).length > 0;
         }
 
         /**
          * Return true if the player has visited a given star location.
          */
         hasVisitedLocation(location: StarLocation): boolean {
-            return contains(this.visited, location);
-        }
-
-        /**
-         * Set a star location as visited.
-         * 
-         * This should always be called for any location, even if it was already marked visited.
-         */
-        setVisited(location: StarLocation): void {
-            add(this.visited, location);
-            this.missions.checkStatus();
+            return contains(this.fleet.visited, location.id);
         }
 
         // Get currently played battle, null when none is in progress
@@ -69,25 +66,5 @@ module TK.SpaceTac {
             this.fleet.setBattle(battle);
             this.missions.checkStatus();
         }
-
-        /**
-         * Exit the current battle unconditionally, if any
-         * 
-         * This does not apply retreat penalties, or battle outcome, only unbind the battle from current session
-         */
-        exitBattle(): void {
-            this.setBattle(null);
-        }
-
-        /**
-         * Revert current battle, and put the player's fleet to its previous location, as if the battle never happened
-         */
-        revertBattle(): void {
-            this.exitBattle();
-
-            if (this.fleet.previous_location) {
-                this.fleet.setLocation(this.fleet.previous_location);
-            }
-        }
     }
 }
diff --git a/src/core/Ship.ts b/src/core/Ship.ts
index fcbbee6..c7d7977 100644
--- a/src/core/Ship.ts
+++ b/src/core/Ship.ts
@@ -120,7 +120,9 @@ module TK.SpaceTac {
             this.play_priority = gen.random() * this.attributes.maneuvrability.get();
         }
 
-        // Return the player owning this ship
+        /**
+         * Return the player that plays this ship
+         */
         getPlayer(): Player {
             return this.fleet.player;
         }
@@ -129,7 +131,7 @@ module TK.SpaceTac {
          * Check if a player is playing this ship
          */
         isPlayedBy(player: Player): boolean {
-            return this.getPlayer().is(player);
+            return player.is(this.fleet.player);
         }
 
         // get the current battle this ship is engaged in
diff --git a/src/core/StarLocation.ts b/src/core/StarLocation.ts
index 7ecec02..5902d3f 100644
--- a/src/core/StarLocation.ts
+++ b/src/core/StarLocation.ts
@@ -1,3 +1,5 @@
+/// <reference path="../common/RObject.ts" />
+
 module TK.SpaceTac {
     export enum StarLocationType {
         STAR,
@@ -7,34 +9,41 @@ module TK.SpaceTac {
         STATION
     }
 
-    // Point of interest in a star system
-    export class StarLocation {
+    /**
+     * Point of interest in a star system
+     */
+    export class StarLocation extends RObject {
         // Parent star system
-        star: Star;
+        star: Star
 
         // Type of location
-        type: StarLocationType;
+        type: StarLocationType
 
         // Location in the star system
-        x: number;
-        y: number;
+        x: number
+        y: number
 
         // Absolute location in the universe
-        universe_x: number;
-        universe_y: number;
+        universe_x: number
+        universe_y: number
 
         // Destination for jump, if its a WARP location
-        jump_dest: StarLocation | null;
+        jump_dest: StarLocation | null
+
+        // Fleets present at this location (excluding the encounter for now)
+        fleets: Fleet[] = []
 
         // Enemy encounter
-        encounter: Fleet | null = null;
-        encounter_gen = false;
-        encounter_random = RandomGenerator.global;
+        encounter: Fleet | null = null
+        encounter_gen = false
+        encounter_random = RandomGenerator.global
 
         // Shop to buy/sell equipment
-        shop: Shop | null = null;
+        shop: Shop | null = null
 
         constructor(star = new Star(), type: StarLocationType = StarLocationType.PLANET, x: number = 0, y: number = 0) {
+            super();
+
             this.star = star;
             this.type = type;
             this.x = x;
@@ -44,6 +53,13 @@ module TK.SpaceTac {
             this.jump_dest = null;
         }
 
+        /**
+         * Get the universe containing this location
+         */
+        get universe(): Universe {
+            return this.star.universe;
+        }
+
         /**
          * Add a shop in this location
          */
@@ -58,6 +74,22 @@ module TK.SpaceTac {
             this.shop = null;
         }
 
+        /**
+         * Add a fleet to the list of fleets present in this system
+         */
+        addFleet(fleet: Fleet): void {
+            if (add(this.fleets, fleet)) {
+                this.enterLocation(fleet);
+            }
+        }
+
+        /**
+         * Remove a fleet from the list of fleets present in this system
+         */
+        removeFleet(fleet: Fleet): void {
+            remove(this.fleets, fleet);
+        }
+
         /**
          * Check if the location is clear of encounter
          */
@@ -134,7 +166,7 @@ module TK.SpaceTac {
                 variations = [[this.star.level, 4], [this.star.level - 1, 5], [this.star.level + 1, 3], [this.star.level + 3, 2]];
             }
             let [level, enemies] = this.encounter_random.choice(variations);
-            this.encounter = fleet_generator.generate(level, new Player(this.star.universe, "Enemy"), enemies, true);
+            this.encounter = fleet_generator.generate(level, new Player("Enemy"), enemies, true);
         }
 
         /**
diff --git a/src/core/TestTools.ts b/src/core/TestTools.ts
index 7c4419c..158d95d 100644
--- a/src/core/TestTools.ts
+++ b/src/core/TestTools.ts
@@ -4,8 +4,8 @@ module TK.SpaceTac {
 
         // Create a battle between two fleets, with a fixed play order (owned ships, then enemy ships)
         static createBattle(own_ships = 1, enemy_ships = 1): Battle {
-            var fleet1 = new Fleet(new Player(undefined, "Attacker"));
-            var fleet2 = new Fleet(new Player(undefined, "Defender"));
+            var fleet1 = new Fleet(new Player("Attacker"));
+            var fleet2 = new Fleet(new Player("Defender"));
 
             while (own_ships--) {
                 fleet1.addShip();
diff --git a/src/core/Universe.ts b/src/core/Universe.ts
index 5b5666b..c637012 100644
--- a/src/core/Universe.ts
+++ b/src/core/Universe.ts
@@ -9,6 +9,9 @@ module TK.SpaceTac {
         // List of links between star systems
         starlinks: StarLink[] = []
 
+        // Collection of all star locations
+        locations = new RObjectContainer<StarLocation>()
+
         // Radius of the universe
         radius = 5
 
@@ -25,6 +28,13 @@ module TK.SpaceTac {
             return result;
         }
 
+        /**
+         * Update the locations list
+         */
+        updateLocations(): void {
+            this.locations = new RObjectContainer(flatten(this.stars.map(star => star.locations)));
+        }
+
         /**
          * Generates a random universe, with star systems and locations of interest
          * 
@@ -54,6 +64,7 @@ module TK.SpaceTac {
             this.stars.forEach((star: Star) => {
                 star.generate(this.random);
             });
+            this.updateLocations();
             this.addShops();
         }
 
@@ -256,5 +267,12 @@ module TK.SpaceTac {
             let star = minBy(this.stars, star => star.level);
             return star.locations[0];
         }
+
+        /**
+         * Get a location from its ID
+         */
+        getLocation(id: RObjectId | null): StarLocation | null {
+            return id === null ? null : this.locations.get(id);
+        }
     }
 }
diff --git a/src/core/actions/TriggerAction.ts b/src/core/actions/TriggerAction.ts
index 6694089..8f7ee8a 100644
--- a/src/core/actions/TriggerAction.ts
+++ b/src/core/actions/TriggerAction.ts
@@ -58,8 +58,7 @@ module TK.SpaceTac {
                 let battle = ship.getBattle();
                 if (battle) {
                     let harmful = any(this.effects, effect => !effect.isBeneficial());
-                    let player = ship.getPlayer();
-                    let ships = imaterialize(harmful ? battle.ienemies(player, true) : ifilter(battle.iallies(player, true), iship => iship != ship));
+                    let ships = imaterialize(harmful ? battle.ienemies(ship, true) : ifilter(battle.iallies(ship, true), iship => !iship.is(ship)));
                     let nearest = minBy(ships, iship => arenaDistance(ship.location, iship.location));
                     return Target.newFromShip(nearest);
                 } else {
diff --git a/src/core/ai/TacticalAIHelpers.ts b/src/core/ai/TacticalAIHelpers.ts
index 4dc270c..7b3177f 100644
--- a/src/core/ai/TacticalAIHelpers.ts
+++ b/src/core/ai/TacticalAIHelpers.ts
@@ -66,7 +66,7 @@ module TK.SpaceTac {
          * Produce all "direct hit" weapon shots.
          */
         static produceDirectShots(ship: Ship, battle: Battle): TacticalProducer {
-            let enemies = ifilter(battle.iships(), iship => iship.alive && iship.getPlayer() !== ship.getPlayer());
+            let enemies = battle.ienemies(ship, true);
             let weapons = ifilter(getPlayableActions(ship), action => action instanceof TriggerAction);
             return imap(icombine(enemies, weapons), ([enemy, weapon]) => new Maneuver(ship, weapon, Target.newFromShip(enemy)));
         }
@@ -88,7 +88,7 @@ module TK.SpaceTac {
         static produceInterestingBlastShots(ship: Ship, battle: Battle): TacticalProducer {
             // TODO Work with groups of 3, 4 ...
             let weapons = <Iterator<TriggerAction>>ifilter(getPlayableActions(ship), action => action instanceof TriggerAction && action.blast > 0);
-            let enemies = battle.ienemies(ship.getPlayer(), true);
+            let enemies = battle.ienemies(ship, true);
             // FIXME This produces duplicates (x, y) and (y, x)
             let couples = ifilter(icombine(enemies, enemies), ([e1, e2]) => e1 != e2);
             let candidates = ifilter(icombine(weapons, couples), ([weapon, [e1, e2]]) => Target.newFromShip(e1).getDistanceTo(Target.newFromShip(e2)) < weapon.blast * 2);
@@ -173,7 +173,7 @@ module TK.SpaceTac {
          * Evaluate the effect on health to the enemy, between -1 and 1
          */
         static evaluateEnemyHealth(ship: Ship, battle: Battle, maneuver: Maneuver): number {
-            let enemies = imaterialize(battle.ienemies(ship.getPlayer(), true));
+            let enemies = imaterialize(battle.ienemies(ship, true));
             return -TacticalAIHelpers.evaluateHealthEffect(maneuver, enemies);
         }
 
@@ -181,7 +181,7 @@ module TK.SpaceTac {
          * Evaluate the effect on health to allied ships, between -1 and 1
          */
         static evaluateAllyHealth(ship: Ship, battle: Battle, maneuver: Maneuver): number {
-            let allies = imaterialize(battle.iallies(ship.getPlayer(), true));
+            let allies = imaterialize(battle.iallies(ship, true));
             return TacticalAIHelpers.evaluateHealthEffect(maneuver, allies);
         }
 
diff --git a/src/core/missions/ActiveMissions.spec.ts b/src/core/missions/ActiveMissions.spec.ts
index 9de31fb..e17a262 100644
--- a/src/core/missions/ActiveMissions.spec.ts
+++ b/src/core/missions/ActiveMissions.spec.ts
@@ -60,7 +60,7 @@ module TK.SpaceTac.Specs {
             let universe = new Universe();
             universe.generate(4);
             let fleet = new Fleet();
-            fleet.setLocation(universe.getStartLocation(), true);
+            fleet.setLocation(universe.getStartLocation());
 
             let missions = new ActiveMissions();
             let hash = missions.getHash();
diff --git a/src/core/missions/MainStory.spec.ts b/src/core/missions/MainStory.spec.ts
index f753f9a..2652243 100644
--- a/src/core/missions/MainStory.spec.ts
+++ b/src/core/missions/MainStory.spec.ts
@@ -10,15 +10,17 @@ module TK.SpaceTac.Specs {
             });
         }
 
-        function goTo(fleet: Fleet, location: StarLocation, win_encounter = true) {
-            fleet.setLocation(location, true);
-            if (fleet.battle) {
-                fleet.battle.endBattle(win_encounter ? fleet : fleet.battle.fleets[1]);
+        function goTo(session: GameSession, location: StarLocation, win_encounter = true) {
+            session.fleet.setLocation(location);
+
+            let battle = session.getBattle();
+            if (battle) {
+                battle.endBattle(win_encounter ? session.fleet : battle.fleets[1]);
                 if (win_encounter) {
-                    fleet.player.exitBattle();
+                    session.exitBattle();
                     location.clearEncounter();
                 } else {
-                    fleet.player.revertBattle();
+                    session.revertBattle();
                 }
             }
         }
@@ -36,7 +38,7 @@ module TK.SpaceTac.Specs {
             (<MissionPartConversation>story.current_part).skip();
 
             checkPart(story, 1, /^Find your contact in .*$/);
-            goTo(fleet, (<MissionPartGoTo>story.current_part).destination);
+            goTo(session, (<MissionPartGoTo>story.current_part).destination);
 
             checkPart(story, 2, /^Speak with your contact/);
             (<MissionPartConversation>story.current_part).skip();
@@ -45,7 +47,7 @@ module TK.SpaceTac.Specs {
             check.same(fleet.ships.length, fleet_size + 1);
             check.same(fleet.ships[fleet_size].critical, true);
             check.greater(fleet.ships[fleet_size].getAttribute("hull_capacity"), 0);
-            goTo(fleet, (<MissionPartEscort>story.current_part).destination);
+            goTo(session, (<MissionPartEscort>story.current_part).destination);
 
             checkPart(story, 4, /^Listen to .*$/);
             (<MissionPartConversation>story.current_part).skip();
diff --git a/src/core/missions/MainStory.ts b/src/core/missions/MainStory.ts
index 5971c75..b768a79 100644
--- a/src/core/missions/MainStory.ts
+++ b/src/core/missions/MainStory.ts
@@ -14,7 +14,7 @@ module TK.SpaceTac {
             super(universe, fleet, true);
 
             let random = RandomGenerator.global;
-            let start_location = nn(fleet.location);
+            let start_location = nn(universe.getLocation(fleet.location));
             let mission_generator = new MissionGenerator(universe, start_location);
 
             // Arrival
@@ -26,7 +26,7 @@ module TK.SpaceTac {
             // Get in touch with our contact
             let contact_location = randomLocation(random, [start_location.star], [start_location]);
             let contact_character = mission_generator.generateShip(1);
-            contact_character.fleet.setLocation(contact_location, true);
+            contact_character.fleet.setLocation(contact_location);
             this.addPart(new MissionPartGoTo(this, contact_location, `Find your contact in ${contact_location.star.name}`, MissionPartDestinationHint.SYSTEM));
             conversation = this.addPart(new MissionPartConversation(this, [contact_character], "Speak with your contact"));
             conversation.addPiece(contact_character, "Finally, you came!");
diff --git a/src/core/missions/MissionPartCleanLocation.spec.ts b/src/core/missions/MissionPartCleanLocation.spec.ts
index 210ccc6..b70c8a6 100644
--- a/src/core/missions/MissionPartCleanLocation.spec.ts
+++ b/src/core/missions/MissionPartCleanLocation.spec.ts
@@ -15,7 +15,7 @@ module TK.SpaceTac.Specs {
             part.onStarted();
             check.equals(destination.isClear(), false);
 
-            fleet.setLocation(destination, true);
+            fleet.setLocation(destination);
             check.same(part.checkCompleted(), false, "Encounter not clear");
 
             destination.clearEncounter();
@@ -28,7 +28,7 @@ module TK.SpaceTac.Specs {
 
             let universe = new Universe();
             let fleet = new Fleet();
-            fleet.setLocation(destination, true);
+            fleet.setLocation(destination);
             let part = new MissionPartCleanLocation(new Mission(universe, fleet), destination);
 
             check.equals(fleet.battle, null);
diff --git a/src/core/missions/MissionPartCleanLocation.ts b/src/core/missions/MissionPartCleanLocation.ts
index 5ca47f1..53a1672 100644
--- a/src/core/missions/MissionPartCleanLocation.ts
+++ b/src/core/missions/MissionPartCleanLocation.ts
@@ -18,7 +18,7 @@ module TK.SpaceTac {
         onStarted(): void {
             this.destination.setupEncounter();
 
-            if (this.fleet.location == this.destination) {
+            if (this.destination.is(this.fleet.location)) {
                 // Already there, re-enter the location to start the fight
                 let battle = this.destination.enterLocation(this.fleet);
                 if (battle) {
diff --git a/src/core/missions/MissionPartEscort.spec.ts b/src/core/missions/MissionPartEscort.spec.ts
index 873a0d0..6e69613 100644
--- a/src/core/missions/MissionPartEscort.spec.ts
+++ b/src/core/missions/MissionPartEscort.spec.ts
@@ -16,16 +16,16 @@ module TK.SpaceTac.Specs {
             part.onStarted();
             check.contains(fleet.ships, ship);
 
-            fleet.setLocation(destination, true);
+            fleet.setLocation(destination);
             check.same(part.checkCompleted(), false, "Encounter not clear");
 
             destination.clearEncounter();
             check.same(part.checkCompleted(), true, "Encouter cleared");
 
-            fleet.setLocation(new StarLocation(), true);
+            fleet.setLocation(new StarLocation());
             check.same(part.checkCompleted(), false, "Went to another system");
 
-            fleet.setLocation(destination, true);
+            fleet.setLocation(destination);
             check.same(part.checkCompleted(), true, "Back at destination");
             check.contains(fleet.ships, ship);
 
diff --git a/src/core/missions/MissionPartGoTo.spec.ts b/src/core/missions/MissionPartGoTo.spec.ts
index 97418a9..5dcc84f 100644
--- a/src/core/missions/MissionPartGoTo.spec.ts
+++ b/src/core/missions/MissionPartGoTo.spec.ts
@@ -11,16 +11,16 @@ module TK.SpaceTac.Specs {
             check.equals(part.title, "Go to Atanax system");
             check.same(part.checkCompleted(), false, "Init location");
 
-            fleet.setLocation(destination, true);
+            fleet.setLocation(destination);
             check.same(part.checkCompleted(), false, "Encounter not clear");
 
             destination.clearEncounter();
             check.same(part.checkCompleted(), true, "Encouter cleared");
 
-            fleet.setLocation(new StarLocation(), true);
+            fleet.setLocation(new StarLocation());
             check.same(part.checkCompleted(), false, "Went to another system");
 
-            fleet.setLocation(destination, true);
+            fleet.setLocation(destination);
             check.same(part.checkCompleted(), true, "Back at destination");
         })
 
diff --git a/src/core/missions/MissionPartGoTo.ts b/src/core/missions/MissionPartGoTo.ts
index 1d40382..d103031 100644
--- a/src/core/missions/MissionPartGoTo.ts
+++ b/src/core/missions/MissionPartGoTo.ts
@@ -25,12 +25,12 @@ module TK.SpaceTac {
         }
 
         checkCompleted(): boolean {
-            return this.fleet.location === this.destination && this.destination.isClear();
+            return this.destination.is(this.fleet.location) && this.destination.isClear();
         }
 
         forceComplete(): void {
             this.destination.clearEncounter();
-            this.fleet.setLocation(this.destination, true);
+            this.fleet.setLocation(this.destination);
         }
 
         getLocationHint(): Star | StarLocation | null {
diff --git a/src/ui/TestGame.ts b/src/ui/TestGame.ts
index 1b4e705..d011768 100644
--- a/src/ui/TestGame.ts
+++ b/src/ui/TestGame.ts
@@ -90,7 +90,8 @@ module TK.SpaceTac.UI.Specs {
             view.splash = false;
 
             let battle = Battle.newQuickRandom();
-            let player = battle.playing_ship ? battle.playing_ship.getPlayer() : new Player();
+            let player = new Player();
+            nn(battle.playing_ship).fleet.setPlayer(player);
 
             return [view, [player, battle]];
         });
diff --git a/src/ui/battle/ActionBar.spec.ts b/src/ui/battle/ActionBar.spec.ts
index 4ca222e..8e997cc 100644
--- a/src/ui/battle/ActionBar.spec.ts
+++ b/src/ui/battle/ActionBar.spec.ts
@@ -13,7 +13,9 @@ module TK.SpaceTac.UI.Specs {
             check.equals(bar.action_icons.length, 0);
 
             // Ship with no equipment (only endturn action)
-            testgame.view.player = ship.getPlayer();
+            let player = new Player();
+            ship.fleet.setPlayer(player);
+            testgame.view.player = player;
             bar.setShip(ship);
             check.equals(bar.action_icons.length, 1);
             check.equals(bar.action_icons[0].action.code, "endturn");
diff --git a/src/ui/battle/ActionBar.ts b/src/ui/battle/ActionBar.ts
index 8191699..41086af 100644
--- a/src/ui/battle/ActionBar.ts
+++ b/src/ui/battle/ActionBar.ts
@@ -225,7 +225,7 @@ module TK.SpaceTac.UI {
         setShip(ship: Ship | null): void {
             this.clearAll();
 
-            if (ship && ship.getPlayer().is(this.battleview.player) && ship.alive) {
+            if (ship && this.battleview.player.is(ship.fleet.player) && ship.alive) {
                 var actions = ship.getAvailableActions();
                 actions.forEach((action: BaseAction) => {
                     this.addAction(ship, action);
diff --git a/src/ui/battle/ArenaShip.ts b/src/ui/battle/ArenaShip.ts
index 4815a9a..cbb7c34 100644
--- a/src/ui/battle/ArenaShip.ts
+++ b/src/ui/battle/ArenaShip.ts
@@ -46,7 +46,7 @@ module TK.SpaceTac.UI {
             this.battleview = parent.view;
 
             this.ship = ship;
-            this.enemy = !this.ship.getPlayer().is(this.battleview.player);
+            this.enemy = !this.battleview.player.is(this.ship.fleet.player);
 
             // Add effects radius
             this.effects_radius = new Phaser.Graphics(this.game);
@@ -121,7 +121,7 @@ module TK.SpaceTac.UI {
             this.updateEffectsRadius();
 
             // Set location
-            if (this.battleview.battle.cycle == 1 && this.battleview.battle.play_index == 0 && ship.alive && ship.fleet.player === this.battleview.player) {
+            if (this.battleview.battle.cycle == 1 && this.battleview.battle.play_index == 0 && ship.alive && this.battleview.player.is(ship.fleet.player)) {
                 this.position.set(ship.arena_x - 500 * Math.cos(ship.arena_angle), ship.arena_y - 500 * Math.sin(ship.arena_angle));
                 this.moveTo(ship.arena_x, ship.arena_y, ship.arena_angle);
             } else {
diff --git a/src/ui/battle/BattleSplash.ts b/src/ui/battle/BattleSplash.ts
index 2dc3069..2cdfb2a 100644
--- a/src/ui/battle/BattleSplash.ts
+++ b/src/ui/battle/BattleSplash.ts
@@ -20,7 +20,7 @@ module TK.SpaceTac.UI {
             this.player1.visible = false;
             this.message.addChild(this.player1);
 
-            let player1_name = view.game.add.text(-240, 22, fleet1.player.name, { font: `bold 22pt SpaceTac`, fill: "#154d13" });
+            let player1_name = view.game.add.text(-240, 22, fleet1.name, { font: `bold 22pt SpaceTac`, fill: "#154d13" });
             player1_name.anchor.set(0.5);
             player1_name.angle = -48;
             this.player1.addChild(player1_name);
@@ -41,7 +41,7 @@ module TK.SpaceTac.UI {
             this.player2.visible = false;
             this.message.addChild(this.player2);
 
-            let player2_name = view.game.add.text(-240, 22, fleet2.player.name, { font: `bold 22pt SpaceTac`, fill: "#651713" });
+            let player2_name = view.game.add.text(-240, 22, fleet2.name, { font: `bold 22pt SpaceTac`, fill: "#651713" });
             player2_name.anchor.set(0.5);
             player2_name.angle = -228;
             this.player2.addChild(player2_name);
diff --git a/src/ui/battle/BattleView.ts b/src/ui/battle/BattleView.ts
index 49091cd..8cba1e3 100644
--- a/src/ui/battle/BattleView.ts
+++ b/src/ui/battle/BattleView.ts
@@ -136,8 +136,8 @@ module TK.SpaceTac.UI {
             this.inputs.bind("Escape", "Cancel action", () => this.action_bar.actionEnded());
             range(10).forEach(i => this.inputs.bind(`Numpad${i % 10}`, `Action/target ${i}`, () => this.numberPressed(i)));
             range(10).forEach(i => this.inputs.bind(`Digit${i % 10}`, `Action/target ${i}`, () => this.numberPressed(i)));
-            this.inputs.bindCheat("w", "Win current battle", () => this.actual_battle.cheats.win());
-            this.inputs.bindCheat("x", "Lose current battle", () => this.actual_battle.cheats.lose());
+            this.inputs.bindCheat("w", "Win current battle", () => nn(this.player.getCheats()).win());
+            this.inputs.bindCheat("x", "Lose current battle", () => nn(this.player.getCheats()).lose());
             this.inputs.bindCheat("a", "Use AI to play", () => this.playAI());
 
             // "Battle" animation, then start processing the log
@@ -286,7 +286,7 @@ module TK.SpaceTac.UI {
         cursorClicked(): void {
             if (this.targetting.active) {
                 this.validationPressed();
-            } else if (this.ship_hovered && this.ship_hovered.getPlayer().is(this.player) && this.interacting) {
+            } else if (this.ship_hovered && this.player.is(this.ship_hovered.fleet.player) && this.interacting) {
                 this.character_sheet.show(this.ship_hovered, undefined, undefined, false);
                 this.setShipHovered(null);
             }
@@ -351,7 +351,7 @@ module TK.SpaceTac.UI {
             if (battle.outcome) {
                 this.setInteractionEnabled(false);
 
-                this.gameui.session.setBattleEnded();
+                this.session.setBattleEnded();
 
                 battle.stats.processLog(battle.log, this.player.fleet);
 
@@ -365,7 +365,7 @@ module TK.SpaceTac.UI {
          * Exit the battle, and go back to map
          */
         exitBattle() {
-            this.player.exitBattle();
+            this.session.exitBattle();
             this.game.state.start('router');
         }
 
@@ -373,7 +373,7 @@ module TK.SpaceTac.UI {
          * Revert the battle, and go back to map
          */
         revertBattle() {
-            this.player.revertBattle();
+            this.session.revertBattle();
             this.game.state.start('router');
         }
     }
diff --git a/src/ui/battle/OutcomeDialog.ts b/src/ui/battle/OutcomeDialog.ts
index 09dc1c1..e4b472d 100644
--- a/src/ui/battle/OutcomeDialog.ts
+++ b/src/ui/battle/OutcomeDialog.ts
@@ -35,7 +35,7 @@ module TK.SpaceTac.UI {
         refreshContent(): void {
             let parent = this.battleview;
             let outcome = this.outcome;
-            let victory = outcome.winner && (outcome.winner.player == this.player);
+            let victory = outcome.winner && this.player.is(outcome.winner.player);
 
             this.clearContent();
 
diff --git a/src/ui/battle/ShipList.spec.ts b/src/ui/battle/ShipList.spec.ts
index b76b01b..86a5342 100644
--- a/src/ui/battle/ShipList.spec.ts
+++ b/src/ui/battle/ShipList.spec.ts
@@ -7,13 +7,15 @@ module TK.SpaceTac.UI.Specs {
         function createList(): ShipList {
             let view = testgame.view;
             let battle = new Battle();
+            let player = new Player();
+            battle.fleets[0].setPlayer(player);
             let tactical_mode = new Toggle();
             let ship_buttons = {
                 cursorOnShip: nop,
                 cursorOffShip: nop,
                 cursorClicked: nop,
             };
-            let list = new ShipList(view, battle, battle.fleets[0].player, tactical_mode, ship_buttons);
+            let list = new ShipList(view, battle, player, tactical_mode, ship_buttons);
             return list;
         }
 
diff --git a/src/ui/battle/ShipTooltip.spec.ts b/src/ui/battle/ShipTooltip.spec.ts
index e9ff635..0a7d91b 100644
--- a/src/ui/battle/ShipTooltip.spec.ts
+++ b/src/ui/battle/ShipTooltip.spec.ts
@@ -5,7 +5,6 @@ module TK.SpaceTac.UI.Specs {
         test.case("fills ship details", check => {
             let tooltip = new ShipTooltip(testgame.view);
             let ship = testgame.view.battle.play_order[2];
-            ship.fleet.player.name = "Phil";
             ship.name = "Fury";
             ship.model = new ShipModel("fake", "Fury");
             ship.listEquipment().forEach(equ => equ.detach());
diff --git a/src/ui/battle/ShipTooltip.ts b/src/ui/battle/ShipTooltip.ts
index 0514576..c653e6c 100644
--- a/src/ui/battle/ShipTooltip.ts
+++ b/src/ui/battle/ShipTooltip.ts
@@ -30,7 +30,7 @@ module TK.SpaceTac.UI {
                 portrait.scale.set(0.5);
             });
 
-            let enemy = !ship.getPlayer().is(this.battleview.player);
+            let enemy = !this.battleview.player.is(ship.fleet.player);
             builder.text(ship.getName(), 168, 0, { color: enemy ? "#cc0d00" : "#ffffff", size: 22, bold: true });
 
             if (ship.alive) {
diff --git a/src/ui/common/UIConversation.ts b/src/ui/common/UIConversation.ts
index 803ca62..234eeb2 100644
--- a/src/ui/common/UIConversation.ts
+++ b/src/ui/common/UIConversation.ts
@@ -139,7 +139,7 @@ module TK.SpaceTac.UI {
             style.image_caption = ship.getName(false);
             style.image_size = 256;
 
-            let own = ship.getPlayer() == this.view.gameui.session.player;
+            let own = this.view.gameui.session.player.is(ship.fleet.player);
             this.setCurrentMessage(style, content, 900, 300, own ? 0.1 : 0.9, own ? 0.2 : 0.8);
         }
 
diff --git a/src/ui/map/FleetDisplay.ts b/src/ui/map/FleetDisplay.ts
index bdd89f9..140718e 100644
--- a/src/ui/map/FleetDisplay.ts
+++ b/src/ui/map/FleetDisplay.ts
@@ -26,8 +26,9 @@ module TK.SpaceTac.UI {
 
             this.updateShipSprites();
 
-            if (fleet.location) {
-                this.position.set(fleet.location.star.x + fleet.location.x, fleet.location.star.y + fleet.location.y);
+            let location = this.map.universe.getLocation(fleet.location);
+            if (location) {
+                this.position.set(location.star.x + location.x, location.star.y + location.y);
             }
             this.scale.set(SCALING, SCALING);
 
@@ -54,7 +55,7 @@ module TK.SpaceTac.UI {
         }
 
         get location(): StarLocation {
-            return this.fleet.location || new StarLocation();
+            return this.map.universe.getLocation(this.fleet.location) || new StarLocation();
         }
 
         /**
@@ -90,9 +91,10 @@ module TK.SpaceTac.UI {
          * Make the fleet move to another location in the same system
          */
         moveToLocation(location: StarLocation, speed = 1, on_leave: ((duration: number) => any) | null = null, on_finished: Function | null = null) {
-            if (this.fleet.location && location != this.fleet.location) {
-                let dx = location.universe_x - this.fleet.location.universe_x;
-                let dy = location.universe_y - this.fleet.location.universe_y;
+            let fleet_location = this.map.universe.getLocation(this.fleet.location);
+            if (fleet_location && this.fleet.move(location)) {
+                let dx = location.universe_x - fleet_location.universe_x;
+                let dy = location.universe_y - fleet_location.universe_y;
                 let distance = Math.sqrt(dx * dx + dy * dy);
                 let angle = Math.atan2(dx, dy);
                 this.map.current_location.setFleetMoving(true);
@@ -103,7 +105,6 @@ module TK.SpaceTac.UI {
                     }
                     let tween = this.game.tweens.create(this.position).to({ x: this.x + dx, y: this.y + dy }, duration, Phaser.Easing.Cubic.Out);
                     tween.onComplete.addOnce(() => {
-                        this.fleet.setLocation(location);
                         if (this.fleet.battle) {
                             this.game.state.start("router");
                         } else {
diff --git a/src/ui/map/MissionsDialog.ts b/src/ui/map/MissionsDialog.ts
index 96bf968..4ce361d 100644
--- a/src/ui/map/MissionsDialog.ts
+++ b/src/ui/map/MissionsDialog.ts
@@ -13,7 +13,7 @@ module TK.SpaceTac.UI {
 
             this.shop = shop;
             this.player = player;
-            this.location = player.fleet.location || new StarLocation();
+            this.location = view.session.getLocation();
             this.on_change = on_change || (() => null);
 
             this.refresh();
diff --git a/src/ui/map/StarSystemDisplay.spec.ts b/src/ui/map/StarSystemDisplay.spec.ts
index adac832..39a82e1 100644
--- a/src/ui/map/StarSystemDisplay.spec.ts
+++ b/src/ui/map/StarSystemDisplay.spec.ts
@@ -4,7 +4,7 @@ module TK.SpaceTac.UI.Specs {
 
         test.case("displays a badge with the current state for a star location", check => {
             let mapview = testgame.view;
-            let location = nn(mapview.player.fleet.location);
+            let location = mapview.player_fleet.location;
 
             let ssdisplay = nn(first(mapview.starsystems, ss => ss.starsystem == location.star));
 
@@ -15,7 +15,7 @@ module TK.SpaceTac.UI.Specs {
             ssdisplay.updateInfo(2, true);
             check.equals(ldisplay[2].name, "map-status-unvisited");
 
-            mapview.player.setVisited(ldisplay[0]);
+            mapview.player.fleet.visited.push(ldisplay[0].id);
             ssdisplay.updateInfo(2, true);
             check.equals(ldisplay[2].name, "map-status-enemy");
 
diff --git a/src/ui/map/StarSystemDisplay.ts b/src/ui/map/StarSystemDisplay.ts
index 3e5349f..af1f1a3 100644
--- a/src/ui/map/StarSystemDisplay.ts
+++ b/src/ui/map/StarSystemDisplay.ts
@@ -50,7 +50,7 @@ module TK.SpaceTac.UI {
                     let visited = this.player.hasVisitedLocation(location);
                     let shop = (visited && !location.encounter && location.shop) ? " (dockyard present)" : "";
 
-                    if (location == this.player.fleet.location) {
+                    if (location.is(this.player.fleet.location)) {
                         return `Current fleet location${shop}`;
                     } else {
                         let loctype = StarLocationType[location.type].toLowerCase();
diff --git a/src/ui/map/UniverseMapView.ts b/src/ui/map/UniverseMapView.ts
index 9bae4ad..b6ac100 100644
--- a/src/ui/map/UniverseMapView.ts
+++ b/src/ui/map/UniverseMapView.ts
@@ -210,7 +210,7 @@ module TK.SpaceTac.UI {
 
             this.starsystems.forEach(system => system.updateInfo(this.zoom, system.starsystem == current_star));
 
-            this.actions.setFromLocation(this.player.fleet.location, this);
+            this.actions.setFromLocation(this.session.getLocation(), this);
 
             this.missions.checkUpdate();
             this.conversation.updateFromMissions(this.player.missions, () => this.checkMissionsUpdate());
@@ -226,7 +226,7 @@ module TK.SpaceTac.UI {
         revealAll(): void {
             this.universe.stars.forEach(star => {
                 star.locations.forEach(location => {
-                    this.player.setVisited(location);
+                    this.player.fleet.setVisited(location);
                 });
             });
             this.refresh();
@@ -276,7 +276,7 @@ module TK.SpaceTac.UI {
          * Set the current zoom level (0, 1 or 2)
          */
         setZoom(level: number, duration = 500) {
-            let current_star = this.player.fleet.location ? this.player.fleet.location.star : null;
+            let current_star = this.session.getLocation().star;
             if (!current_star || level <= 0) {
                 this.setCamera(0, 0, this.universe.radius * 2, duration);
                 this.setLinksAlpha(1, duration);
@@ -300,7 +300,7 @@ module TK.SpaceTac.UI {
          * This will only work if current location is a warp
          */
         doJump(): void {
-            let location = this.player.fleet.location;
+            let location = this.session.getLocation();
             if (this.interactive && location && location.type == StarLocationType.WARP && location.jump_dest) {
                 let dest_location = location.jump_dest;
                 let dest_star = dest_location.star;
@@ -321,7 +321,7 @@ module TK.SpaceTac.UI {
          * This will only work if current location has a dockyard
          */
         openShop(): void {
-            let location = this.player.fleet.location;
+            let location = this.session.getLocation();
             if (this.interactive && location && location.shop) {
                 this.character_sheet.setShop(location.shop);
                 this.character_sheet.show(this.player.fleet.ships[0]);
@@ -334,7 +334,7 @@ module TK.SpaceTac.UI {
          * This will only work if current location has a dockyard
          */
         openMissions(): void {
-            let location = this.player.fleet.location;
+            let location = this.session.getLocation();
             if (this.interactive && location && location.shop) {
                 new MissionsDialog(this, location.shop, this.player, () => this.checkMissionsUpdate());
             }
@@ -344,7 +344,7 @@ module TK.SpaceTac.UI {
          * Move the fleet to another location
          */
         moveToLocation(dest: StarLocation): void {
-            if (this.interactive && dest != this.player.fleet.location) {
+            if (this.interactive && !dest.is(this.player.fleet.location)) {
                 this.setInteractionEnabled(false);
                 this.player_fleet.moveToLocation(dest, 1, null, () => {
                     this.setInteractionEnabled(true);