diff --git a/.github/workflows/realm.yml b/.github/workflows/realm.yml
index 20eff82..498e717 100644
--- a/.github/workflows/realm.yml
+++ b/.github/workflows/realm.yml
@@ -20,5 +20,5 @@ jobs:
       - uses: actions/setup-go@v4
         with:
           go-version: 'stable'
-      - run: go install github.com/gnolang/gno/gnovm/cmd/gno
-      - run: gno test --verbose ./realm
+      - run: go mod download -x
+      - run: go run github.com/gnolang/gno/gnovm/cmd/gno test -verbose -run 'Test([^P]|P[^e])' ./realm
diff --git a/.github/workflows/rules.yml b/.github/workflows/rules.yml
new file mode 100644
index 0000000..ab4b62a
--- /dev/null
+++ b/.github/workflows/rules.yml
@@ -0,0 +1,22 @@
+name: rules
+
+on:
+  pull_request:
+    paths:
+      - "realm/rules.gno"
+  push:
+    branches:
+      - master
+      - main
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v4
+        with:
+          go-version: 'stable'
+      - run: go mod download -x
+      - run: go run github.com/gnolang/gno/gnovm/cmd/gno test -verbose -run 'TestPerft' ./realm
diff --git a/realm/chess.gno b/realm/chess.gno
index 9703658..106aa73 100644
--- a/realm/chess.gno
+++ b/realm/chess.gno
@@ -513,7 +513,14 @@ func Resign(gameID string) string {
 	std.AssertOriginCall()
 
 	g := getGame(gameID, true)
+	err := resign(g)
+	if err != nil {
+		panic(err.Error())
+	}
+	return g.json()
+}
 
+func resign(g *Game) error {
 	caller := std.GetOrigCaller()
 	switch caller {
 	case g.Black:
@@ -523,12 +530,12 @@ func Resign(gameID string) string {
 		g.State = GameStateResigned
 		g.Winner = WinnerBlack
 	default:
-		panic("you are not involved in this game")
+		return errors.New("you are not involved in this game")
 	}
 	g.DrawOfferer = nil
 	g.saveResult()
 
-	return g.json()
+	return nil
 }
 
 // DrawOffer creates a draw offer in the current game, if one doesn't already
diff --git a/realm/lobby.gno b/realm/lobby.gno
index 8f5db18..894f11b 100644
--- a/realm/lobby.gno
+++ b/realm/lobby.gno
@@ -83,7 +83,16 @@ func LobbyJoin(seconds, increment int) {
 	// Ensure that user's previous games are finished (or timed out).
 	caller := std.GetOrigCaller()
 
-	assertGamesFinished(getUserGames(caller))
+	games := getUserGames(caller)
+	// XXX: temporary to avoid ever prohibiting a user from joining the lobby.
+	// when possible, change back to assertGamesFinished(games)
+	for _, g := range games {
+		if !g.State.IsFinished() {
+			if err := resign(g); err != nil {
+				panic("internal error (could not resign game " + g.ID + "): " + err.Error())
+			}
+		}
+	}
 	assertUserNotInLobby(caller)
 
 	// remove caller from lobbyPlayer2Game, so LobbyGameFound
diff --git a/realm/lobby_test.gno b/realm/lobby_test.gno
index 95a2c58..48a6c0f 100644
--- a/realm/lobby_test.gno
+++ b/realm/lobby_test.gno
@@ -165,7 +165,6 @@ func TestLobbyGameFound(t *testing.T) {
 
 func TestLobbyJoin_HasOpenGames(t *testing.T) {
 	cleanup()
-	std.TestSetOrigCaller(white)
 	g := &Game{
 		ID:    "123",
 		White: white,
@@ -176,12 +175,12 @@ func TestLobbyJoin_HasOpenGames(t *testing.T) {
 	addToUser2Games(white, g)
 	addToUser2Games(black, g)
 
-	defer func() {
-		e := recover()
-		if !strings.Contains(fmt.Sprint(e), "game 123 is not yet finished") {
-			t.Errorf("expecting 'game is not finished' panic, got %v", e)
-		}
-	}()
-
+	std.TestSetOrigCaller(white)
 	LobbyJoin(10*60, 5)
+	if g.State != GameStateResigned {
+		t.Errorf("state wrong: want %d got %d", GameStateResigned, g.State)
+	}
+	if g.Winner != WinnerBlack {
+		t.Errorf("winner wrong: want %q got %q", "black", g.Winner)
+	}
 }