diff --git a/src/routes/api/games/+server.ts b/src/routes/api/games/+server.ts
index d8a1edf..fcaee5e 100644
--- a/src/routes/api/games/+server.ts
+++ b/src/routes/api/games/+server.ts
@@ -17,7 +17,7 @@ export const POST: RequestHandler = async ({ locals }): Promise<Response> => {
 	const { username, sub } = user.payload;
 	const game = new Game();
 
-	game.addPlayer(sub, username);
+	game.addPlayer({ id: sub, username, isReady: false });
 
 	const newListing = createNewListing(game);
 
diff --git a/src/routes/api/games/[gameid]/+server.ts b/src/routes/api/games/[gameid]/+server.ts
index d7f2611..9ec955c 100644
--- a/src/routes/api/games/[gameid]/+server.ts
+++ b/src/routes/api/games/[gameid]/+server.ts
@@ -1,9 +1,16 @@
-import type { GameData } from "$lib/GameData";
+import { isGameData, type GameData } from "$lib/GameData";
 import { isListing } from "$lib/Listing";
-import { readListingById, ServerCollections } from "$lib/server/mongo";
-import { getParam, ResourceId } from "$lib/server/requestTools";
+import { Game } from "$lib/server/Game";
+import { updateListing } from "$lib/server/modifyListing";
+import {
+	readListingById,
+	ServerCollections,
+	writeUpdatedListing,
+} from "$lib/server/mongo";
+import { getBody, getParam, ResourceId } from "$lib/server/requestTools";
 import {
 	badRequestResponse,
+	conflictResponse,
 	notFoundResponse,
 	singleResponse,
 } from "$lib/server/responseBodies";
@@ -24,3 +31,40 @@ export const GET: RequestHandler = async ({ params }): Promise<Response> => {
 
 	return singleResponse(game);
 };
+
+export const PUT: RequestHandler = async ({ request, params }): Promise<Response> => {
+	const id = getParam(params, ResourceId.Game);
+
+	if (!id) {
+		return badRequestResponse("missing gameid parameter");
+	}
+
+	const gameListing = await readListingById(
+		ServerCollections.Games,
+		id,
+		isListing<GameData>,
+	);
+
+	if (!gameListing) {
+		return notFoundResponse();
+	}
+
+	const game = Game.from(gameListing.data);
+	const body = await getBody(request, isGameData);
+
+	if (!body) {
+		return badRequestResponse("missing game data in body");
+	}
+
+	if (!game.isStarted) {
+		if (body.isStarted) {
+			game.start();
+		}
+	} else if (game.isStarted !== body.isStarted) {
+		return conflictResponse();
+	}
+
+	await writeUpdatedListing(ServerCollections.Games, updateListing(gameListing, game));
+
+	return singleResponse(gameListing);
+};
diff --git a/src/routes/api/games/[gameid]/players/[playerid]/+server.ts b/src/routes/api/games/[gameid]/players/[playerid]/+server.ts
index 67a7b18..6866576 100644
--- a/src/routes/api/games/[gameid]/players/[playerid]/+server.ts
+++ b/src/routes/api/games/[gameid]/players/[playerid]/+server.ts
@@ -47,13 +47,6 @@ export const PUT: RequestHandler = async ({ params, request }): Promise<Response
 	const game = Game.from(listing.data);
 	if (game.setPlayerReady(player) === null) return notFoundResponse();
 
-	// TODO: there's a potential race condition here where some player is unreadying as this
-	//       function is running. This should do some kind of check in MongoDB to make sure
-	//       all players are ready if it's starting the game. For now: good enough.
-	if (game.players.every(({ isReady }) => isReady)) {
-		game.start();
-	}
-
 	await writeUpdatedListing(ServerCollections.Games, updateListing(listing, game));
 
 	return singleResponse(game);