diff --git a/SPEC.md b/SPEC.md
index 883625d..a8b419e 100644
--- a/SPEC.md
+++ b/SPEC.md
@@ -165,7 +165,12 @@ A single record represents an entire game. Both players maintain their own copy
           },
           "resultReason": {
             "type": "string",
-            "knownValues": ["checkmate", "resignation", "draw_agreement", "stalemate", "insufficient", "repetition", "fifty_moves"]
+            "knownValues": ["checkmate", "resignation", "agreement", "stalemate", "insufficient", "repetition", "fifty_moves", "abandonment"]
+          },
+          "lastMoveAt": {
+            "type": "string",
+            "format": "datetime",
+            "description": "Timestamp of the most recent move"
           },
           "parentGameUri": {
             "type": "string",
@@ -176,6 +181,11 @@ A single record represents an entire game. Both players maintain their own copy
             "type": "boolean",
             "description": "Whether a draw has been offered by the last moving player"
           },
+          "variant": {
+            "type": "string",
+            "knownValues": ["standard", "really-bad-chess", "chess960"],
+            "description": "Chess variant for this game. Omit for standard chess."
+          },
           "timeControl": {
             "type": "ref",
             "ref": "#timeControl"
@@ -228,6 +238,11 @@ Created when a player wants to start a game. Contains a reference to who they're
           "status": {
             "type": "string",
             "knownValues": ["open", "accepted", "expired", "cancelled"]
+          },
+          "variant": {
+            "type": "string",
+            "knownValues": ["standard", "really-bad-chess", "chess960"],
+            "description": "Chess variant for this challenge. Omit for standard chess."
           }
         }
       }
diff --git a/lexicons/README.md b/lexicons/README.md
index 7e26037..9449b21 100644
--- a/lexicons/README.md
+++ b/lexicons/README.md
@@ -8,8 +8,10 @@ AT Protocol lexicon definitions for checkmate.blue. Namespace: `blue.checkmate.*
 
 Chess game record. Both players maintain their own copy -- White's is the primary, Black's links back via `parentGameUri`. PGN is the source of truth for game state; updated via `putRecord` on each move.
 
+The `variant` field distinguishes non-standard games (e.g. `really-bad-chess`). For variant games with custom starting positions, the FEN is carried in the PGN headers (`[SetUp "1"]` / `[FEN "..."]`), not as a separate record field.
+
 `timeControl` and `moveTimes` are defined but not yet implemented. All games are currently untimed.
 
 ### `blue.checkmate.challenge`
 
-Challenge to play. Can target a specific opponent (by DID) or be left open. Once accepted, `gameUri` is set and `status` moves to `accepted`.
+Challenge to play. Can target a specific opponent (by DID) or be left open. Directed challenges are enforced -- only the named opponent can accept. Once accepted, `gameUri` is set and `status` moves to `accepted`. The `variant` field carries through to the game so the opponent knows what they're accepting.
diff --git a/lexicons/blue.checkmate.challenge.json b/lexicons/blue.checkmate.challenge.json
index 1fb5117..c0d2148 100644
--- a/lexicons/blue.checkmate.challenge.json
+++ b/lexicons/blue.checkmate.challenge.json
@@ -29,10 +29,10 @@
             "knownValues": ["open", "accepted", "expired", "cancelled"],
             "description": "Current challenge status"
           },
-          "challengerColor": {
+          "variant": {
             "type": "string",
-            "knownValues": ["white", "black"],
-            "description": "Color the challenger will play"
+            "knownValues": ["standard", "really-bad-chess", "chess960"],
+            "description": "Chess variant for this challenge. Omit for standard chess."
           }
         }
       }
diff --git a/lexicons/blue.checkmate.game.json b/lexicons/blue.checkmate.game.json
index 677c36e..b4be160 100644
--- a/lexicons/blue.checkmate.game.json
+++ b/lexicons/blue.checkmate.game.json
@@ -82,6 +82,11 @@
             "type": "boolean",
             "description": "Whether a draw has been offered by the last moving player"
           },
+          "variant": {
+            "type": "string",
+            "knownValues": ["standard", "really-bad-chess", "chess960"],
+            "description": "Chess variant for this game. Omit for standard chess."
+          },
           "timeControl": {
             "type": "ref",
             "ref": "#timeControl"
diff --git a/src/lib/types.ts b/src/lib/types.ts
index af23c76..153935a 100644
--- a/src/lib/types.ts
+++ b/src/lib/types.ts
@@ -18,6 +18,7 @@ export interface GameRecord {
 	lastMoveAt?: string;
 	parentGameUri?: string;
 	drawOffered?: boolean;
+	variant?: 'standard' | 'really-bad-chess' | 'chess960';
 	timeControl?: TimeControl;
 	moveTimes?: number[];
 }
@@ -29,7 +30,7 @@ export interface ChallengeRecord {
 	opponent?: string;
 	gameUri?: string;
 	status: 'open' | 'accepted' | 'expired' | 'cancelled';
-	challengerColor?: 'white' | 'black';
+	variant?: 'standard' | 'really-bad-chess' | 'chess960';
 }
 
 export type PlayerColor = 'white' | 'black';
diff --git a/src/routes/challenge/[did]/[rkey]/+page.svelte b/src/routes/challenge/[did]/[rkey]/+page.svelte
index 6e1bd9d..eac6639 100644
--- a/src/routes/challenge/[did]/[rkey]/+page.svelte
+++ b/src/routes/challenge/[did]/[rkey]/+page.svelte
@@ -41,8 +41,17 @@
 		loading = false;
 	}
 
+	const isDirectedAtSomeoneElse = $derived(
+		(challenge as ChallengeRecord | null)?.opponent != null &&
+		(challenge as ChallengeRecord | null)?.opponent !== auth.did
+	);
+
 	async function acceptChallenge() {
 		if (!auth.agent || !auth.did || !challenge?.gameUri) return;
+		if (isDirectedAtSomeoneElse) {
+			error = 'This challenge is for a specific player';
+			return;
+		}
 		accepting = true;
 		error = '';
 
@@ -118,6 +127,8 @@
 						</p>
 					{/if}
 				</div>
+			{:else if isDirectedAtSomeoneElse}
+				<p class="text-text-secondary">This challenge is for a specific player.</p>
 			{:else}
 				<button
 					onclick={acceptChallenge}
diff --git a/src/routes/play/+page.svelte b/src/routes/play/+page.svelte
index 396b0d1..23b6a92 100644
--- a/src/routes/play/+page.svelte
+++ b/src/routes/play/+page.svelte
@@ -45,10 +45,6 @@
 				status: 'waiting',
 			});
 
-			const challengerColor: 'white' | 'black' = colorChoice === 'random'
-				? (white === auth.did ? 'white' : 'black')
-				: colorChoice;
-
 			const challengeResult = await createChallenge(auth.agent, {
 				opponent: opponentDid,
 			});
@@ -56,7 +52,6 @@
 			await updateChallenge(auth.agent, challengeResult.rkey, {
 				gameUri: gameResult.uri,
 				status: 'open',
-				challengerColor,
 			});
 
 			goto(`/game/${auth.did}/${gameResult.rkey}`);