diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 000000000..593c1d730
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+  "codium.codeCompletion.enable": false
+}
diff --git a/src/core/gamemodes/NukeWarsRuleSet.ts b/src/core/gamemodes/NukeWarsRuleSet.ts
new file mode 100644
index 000000000..7a25392d3
--- /dev/null
+++ b/src/core/gamemodes/NukeWarsRuleSet.ts
@@ -0,0 +1,36 @@
+/* Centralized rules for Nuke Wars gamemode */
+import { GameMapType, GameMode, TeamGameType } from "../game/Game";
+import { UnitType } from "../units/UnitType";
+
+export const NukeWarsConstants = {
+  PREP_DURATION_MINUTES: 3,
+  LOSS_TERRITORY_THRESHOLD_PERCENT: 5,
+  SAM_INTERCEPT: new Map<UnitType, number>([
+    [UnitType.AtomBomb, 1.0],
+    [UnitType.HydrogenBomb, 0.8],
+  ]),
+};
+
+export function isNukeWars(
+  gameMode: GameMode,
+  teamGameType?: TeamGameType,
+): boolean {
+  return gameMode === GameMode.Team && teamGameType === TeamGameType.NukeWars;
+}
+
+export function isBaikal(gameMap: GameMapType): boolean {
+  return gameMap === GameMapType.Baikal;
+}
+
+// Updated per request: Only block MIRV. Everything else allowed subject to other spatial/phase rules.
+export function isAllowedUnit(unit: UnitType): boolean {
+  return unit !== UnitType.MIRV;
+}
+
+export function isMissileAllowedToCrossMidpoint(unit: UnitType): boolean {
+  return unit === UnitType.AtomBomb || unit === UnitType.HydrogenBomb; // MIRV blocked above
+}
+
+export function getSamInterceptChance(unit: UnitType): number | undefined {
+  return NukeWarsConstants.SAM_INTERCEPT.get(unit);
+}