diff --git a/src/core/execution/TransportShipExecution.ts b/src/core/execution/TransportShipExecution.ts
index efa3096b6..e166a8abb 100644
--- a/src/core/execution/TransportShipExecution.ts
+++ b/src/core/execution/TransportShipExecution.ts
@@ -105,19 +105,20 @@ export class TransportShipExecution implements Execution {
       return;
     }
 
-    // In Nuke Wars on Baikal, prevent transport ships from crossing the midpoint
+    // In Nuke Wars on Baikal, prevent transport ships from entering enemy territory
     const gc = this.mg.config().gameConfig();
     if (
       gc.gameMode === GameMode.NukeWars &&
-      gc.gameMap === GameMapType.Baikal
+      gc.gameMap === GameMapType.Baikal &&
+      this.dst !== null
     ) {
-      const mapWidth = this.mg.width();
-      const wantLeft = this.attacker.smallID() % 2 === 1;
-      const dstX = this.mg.x(this.dst);
-      const dstLeft = dstX < Math.floor(mapWidth / 2);
-      if (wantLeft !== dstLeft) {
+      const dstOwner = this.mg.owner(this.dst);
+      if (
+        dstOwner.isPlayer() &&
+        !this.attacker.isOnSameTeam(dstOwner as Player)
+      ) {
         this.mg.displayMessage(
-          "Transport ships cannot cross the midpoint in Nuke Wars",
+          "Transport ships cannot enter enemy team territory in Nuke Wars",
           MessageType.ATTACK_FAILED,
           this.attacker.id(),
         );
diff --git a/src/core/game/PlayerImpl.ts b/src/core/game/PlayerImpl.ts
index ac8ac5b97..71d1998b2 100644
--- a/src/core/game/PlayerImpl.ts
+++ b/src/core/game/PlayerImpl.ts
@@ -909,14 +909,17 @@ export class PlayerImpl implements Player {
       return true;
     }
 
+    const team = this.team();
+    if (!team) return false;
+
+    // Simple geometric split:
+    // Team 1 (first team) gets left half (x < width/2)
+    // Team 2 (second team) gets right half (x >= width/2)
     const x = this.mg.x(tile);
     const mapWidth = this.mg.width();
     const midpoint = Math.floor(mapWidth / 2);
-    const team = this.team();
 
-    if (!team) return false;
-
-    // Team 1 spawns on left side, Team 2 on right side
+    // Team 1 gets left half, Team 2 gets right half
     const isTeam1 = team === this.mg.teams()[0];
     return isTeam1 ? x < midpoint : x >= midpoint;
   }
@@ -936,15 +939,19 @@ export class PlayerImpl implements Player {
       gc.gameMode === GameMode.NukeWars &&
       gc.gameMap === GameMapType.Baikal
     ) {
-      // Ships must stay on their team's side
+      // Ships cannot enter enemy team spawn zones
       if (
         unitType === UnitType.Warship ||
         unitType === UnitType.TradeShip ||
         unitType === UnitType.TransportShip
       ) {
-        if (!this.isInTeamSpawnZone(targetTile)) {
+        const targetOwner = this.mg.owner(targetTile);
+        if (
+          targetOwner.isPlayer() &&
+          !this.isOnSameTeam(targetOwner as Player)
+        ) {
           this.mg.displayMessage(
-            "Ships cannot cross the midpoint in Nuke Wars",
+            "Ships cannot enter enemy team territory in Nuke Wars",
             MessageType.ATTACK_FAILED,
             this.id(),
           );
@@ -1087,9 +1094,17 @@ export class PlayerImpl implements Player {
   }
 
   private validStructureSpawnTiles(tile: TileRef): TileRef[] {
-    if (this.mg.owner(tile) !== this) {
+    const owner = this.mg.owner(tile);
+    const gc = this.mg.config().gameConfig();
+    // In NukeWars prep phase, allow building in team territory
+    if (gc.gameMode === GameMode.NukeWars && this.mg.inPreparationPhase()) {
+      if (!owner.isPlayer() || !this.isOnSameTeam(owner as Player)) {
+        return [];
+      }
+    } else if (owner !== this) {
       return [];
     }
+
     const searchRadius = 15;
     const searchRadiusSquared = searchRadius ** 2;
     const types = Object.values(UnitType).filter((unitTypeValue) => {
diff --git a/src/core/game/TransportShipUtils.ts b/src/core/game/TransportShipUtils.ts
index b93be3333..862f533e5 100644
--- a/src/core/game/TransportShipUtils.ts
+++ b/src/core/game/TransportShipUtils.ts
@@ -20,11 +20,20 @@ export function canBuildTransportShip(
   }
 
   const other = game.owner(tile);
-  if (other === player) {
-    return false;
-  }
-  if (other.isPlayer() && player.isFriendly(other)) {
-    return false;
+  // During NukeWars, don't block transport ships between team members
+  const gc = game.config().gameConfig();
+  if (gc.gameMode !== GameMode.NukeWars) {
+    if (other === player) {
+      return false;
+    }
+    if (other.isPlayer() && player.isFriendly(other)) {
+      return false;
+    }
+  } else {
+    // In NukeWars, only block sending to enemy teams
+    if (other.isPlayer() && player.isOnSameTeam(other as Player)) {
+      return false;
+    }
   }
 
   if (game.isOceanShore(dst)) {
@@ -73,17 +82,16 @@ export function canBuildTransportShip(
 
   for (const t of sorted) {
     if (game.owner(t) === player) {
-      // Block cross-midpoint lake deployments in Nuke Wars on Baikal
+      // Block lake deployments into enemy team territory in Nuke Wars
       const gc = game.config().gameConfig();
       if (
         gc.gameMode === GameMode.NukeWars &&
         gc.gameMap === GameMapType.Baikal
       ) {
-        const mapWidth = game.width();
-        const wantLeft = player.smallID() % 2 === 1;
-        const tX = game.x(t);
-        const tLeft = tX < Math.floor(mapWidth / 2);
-        if (wantLeft !== tLeft) return false;
+        const tileOwner = game.owner(t);
+        if (tileOwner.isPlayer() && !player.isOnSameTeam(tileOwner as Player)) {
+          return false;
+        }
       }
       return transportShipSpawn(game, player, t);
     }