1 files changed, 17 insertions, 5 deletions
diff --git a/internal/casino/manager.go b/internal/casino/manager.go
index a9bab92..38b754f 100644
--- a/internal/casino/manager.go
+++ b/internal/casino/manager.go
@@ -26,7 +26,11 @@ func tableKey(roomID int, tableID string) string {
 	return fmt.Sprintf("%d:%s", roomID, tableID)
 }
 
+// EnsureMachine returns nil for an invalid or unsupported configuration.
 func (m *Manager) EnsureMachine(roomID int, cfg MachineConfig) *Machine {
+	if cfg.Validate() != nil {
+		return nil
+	}
 	cfg = cfg.Normalize()
 	key := tableKey(roomID, cfg.ID)
 	m.mu.Lock()
@@ -34,14 +38,18 @@ func (m *Manager) EnsureMachine(roomID int, cfg MachineConfig) *Machine {
 	if machine := m.machines[key]; machine != nil {
 		return machine
 	}
-	machine := newMachine(roomID, cfg, m.rng)
+	// Only the manager consumes its RNG, under m.mu. Each game owns an
+	// independent stream protected by that game's lock.
+	machine := newMachine(roomID, cfg, rand.New(rand.NewSource(m.rng.Int63())))
 	m.machines[key] = machine
 	return machine
 }
 
-// EnsureTable returns the table for cfg, or nil when cfg.Game has no
-// multiplayer table implementation.
+// EnsureTable returns nil for an invalid or unsupported configuration.
 func (m *Manager) EnsureTable(roomID int, cfg TableConfig) *Table {
+	if cfg.Validate() != nil {
+		return nil
+	}
 	cfg = cfg.Normalize()
 	key := tableKey(roomID, cfg.ID)
 	m.mu.Lock()
@@ -49,7 +57,7 @@ func (m *Manager) EnsureTable(roomID int, cfg TableConfig) *Table {
 	if table := m.tables[key]; table != nil {
 		return table
 	}
-	table := newTable(roomID, cfg, m.rng)
+	table := newTable(roomID, cfg, rand.New(rand.NewSource(m.rng.Int63())))
 	if table == nil {
 		return nil
 	}
@@ -122,7 +130,11 @@ func (m *Manager) withMachine(roomID int, machineID string, fn func(*Machine) []
 }
 
 func (m *Manager) JoinMachine(roomID int, cfg MachineConfig, name string) []Event {
-	return m.EnsureMachine(roomID, cfg).join(name)
+	machine := m.EnsureMachine(roomID, cfg)
+	if machine == nil {
+		return []Event{{RoomID: roomID, TableID: cfg.ID, Type: EventResult, PrivateTo: name, Message: "That game is not available here."}}
+	}
+	return machine.join(name)
 }
 
 func (m *Manager) SetMachineBet(roomID int, machineID, name string, amount int, wallet Wallet) []Event {