diff --git a/OpenPolytopia.Common/City.cs b/OpenPolytopia.Common/City.cs
index a66f21b..0fc40ca 100644
--- a/OpenPolytopia.Common/City.cs
+++ b/OpenPolytopia.Common/City.cs
@@ -165,9 +165,9 @@ public struct CityData : ITileCustomData {
   /// </remarks>
   public int Owner {
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    get => (int)_inner.GetBits(FOUR_BITS, OWNER_POSITION);
+    get => (int)_inner.GetBits(FIVE_BITS, OWNER_POSITION);
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    set => _inner.SetBits((uint)value, FOUR_BITS, OWNER_POSITION);
+    set => _inner.SetBits((uint)value, FIVE_BITS, OWNER_POSITION);
   }
 
   /// <summary>
diff --git a/OpenPolytopia.Common/Grid.cs b/OpenPolytopia.Common/Grid.cs
index dbc7f14..cc29050 100644
--- a/OpenPolytopia.Common/Grid.cs
+++ b/OpenPolytopia.Common/Grid.cs
@@ -181,10 +181,10 @@ public struct Tile {
   private const int TILEKIND_POSITION = 59;
   private const int TILE_MODIFIER_POSITION = 57;
   private const int TILE_BUILDING_POSITION = 54;
-  private const int TILE_OWNER_POSITION = 50;
-  private const int TILE_BIOME_POSITION = 45;
-  private const int CITY_POSITION = 37;
-  private const int WONDER_POSITION = 33;
+  private const int TILE_OWNER_POSITION = 49;
+  private const int TILE_BIOME_POSITION = 44;
+  private const int CITY_POSITION = 36;
+  private const int WONDER_POSITION = 32;
   private const int CUSTOM_DATA_POSITION = 0;
 
   private const int ONE_BIT = 1;
@@ -202,7 +202,7 @@ public struct Tile {
   /// <remarks>
   /// This is represented as the number of bits set to 1, not as the number itself
   /// </remarks>
-  public const ulong MAX_CUSTOM_DATA_BITS = 8_589_934_591;
+  public const ulong MAX_CUSTOM_DATA_BITS = 4_294_967_295;
 
   /// <summary>
   /// Returns the corresponding modifier enum's <see cref="Type"/> from a <see cref="Kind"/>
@@ -232,11 +232,11 @@ public static Type GetModifier(TileKind kind) =>
   /// <item>[2, 4] -> <see cref="Kind"/></item>
   /// <item>[5, 6] -> Tile modifier</item>
   /// <item>[7, 9] -> Tile buildings</item>
-  /// <item>[10, 13] -> Tile owner; if 0 no owner</item>
-  /// <item>[14, 18] -> Tribe biome</item>
-  /// <item>[19, 26] -> City ID; if 0 no city</item>
-  /// <item>[27, 30] -> Wonder</item>
-  /// <item>[31, 63] -> Custom data</item>
+  /// <item>[10, 14] -> Tile owner; if 0 no owner</item>
+  /// <item>[15, 19] -> Tribe biome</item>
+  /// <item>[20, 27] -> City ID; if 0 no city</item>
+  /// <item>[28, 31] -> Wonder</item>
+  /// <item>[32, 63] -> Custom data</item>
   /// </list>
   /// </summary>
   private ulong _inner;
@@ -299,9 +299,9 @@ public int Building {
   /// </remarks>
   public int Owner {
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    get => (int)_inner.GetBits(FOUR_BITS, TILE_OWNER_POSITION);
+    get => (int)_inner.GetBits(FIVE_BITS, TILE_OWNER_POSITION);
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    set => _inner.SetBits((ulong)value, FOUR_BITS, TILE_OWNER_POSITION);
+    set => _inner.SetBits((ulong)value, FIVE_BITS, TILE_OWNER_POSITION);
   }
 
   /// <summary>
diff --git a/OpenPolytopia.Common/TerrainGeneration.cs b/OpenPolytopia.Common/TerrainGeneration.cs
index a38f63c..beb43f3 100644
--- a/OpenPolytopia.Common/TerrainGeneration.cs
+++ b/OpenPolytopia.Common/TerrainGeneration.cs
@@ -56,9 +56,12 @@ public class TerrainGeneration(
   // one village every VILLAGE_DIVISOR eligible tiles
   private const int VILLAGE_DIVISOR = 9;
 
-  // Tile.City is 8 bits so there can't be more than 255 cities in a grid
+  // registering more cities than this makes CityManager throw
   private const int MAX_CITIES = 255;
 
+  // biggest lobby a game can be started from
+  private const int MAX_PLAYERS = 16;
+
   // zone map values, used for village spacing and resource spawning
   private const byte ZONE_FREE = 0;
   private const byte ZONE_BORDER = 1;
@@ -128,17 +131,16 @@ public async Task GenerateMapAsync() {
         "the map has already been generated; create a new TerrainGeneration to generate another map");
     }
 
-    // Tile.Owner is 4 bits, so there can't be more than 15 players
-    if (players.Length is 0 or > 15) {
+    if (players.Length is 0 or > MAX_PLAYERS) {
       throw new InvalidOperationException(
-        $"invalid number of players: {players.Length}; must be between 1 and 15");
+        $"invalid number of players: {players.Length}; must be between 1 and {MAX_PLAYERS}");
     }
 
     var seenIds = 0;
     foreach (var player in players) {
-      // player ids must fit in the 4-bit Tile.Owner field, where 0 means no owner
-      if (player.Id is < 1 or > 15) {
-        throw new InvalidOperationException($"invalid player id: {player.Id}; must be between 1 and 15");
+      // 0 is the id of the tiles nobody owns, so no player can have it
+      if (player.Id is < 1 or > MAX_PLAYERS) {
+        throw new InvalidOperationException($"invalid player id: {player.Id}; must be between 1 and {MAX_PLAYERS}");
       }
 
       // a duplicate id would merge the territories of two players