diff --git a/src/state/fsm/lobby/events.go b/src/state/fsm/lobby/events.go
index 4afec46..0891180 100644
--- a/src/state/fsm/lobby/events.go
+++ b/src/state/fsm/lobby/events.go
@@ -2,11 +2,20 @@ package lobby
 
 import (
 	"context"
+	"gitea/price-is-wrong/src/lib/db"
 	lobby "gitea/price-is-wrong/src/state/fsm/lobby/internal"
-	"io"
+	"slices"
 )
 
-func (l *Lobby) withEvent(ctx context.Context, e lobby.Event) error {
+func (l *Lobby) Join(ctx context.Context, id int) error {
+	return l.upsertEvent(ctx, lobby.PlayerJoin{ID: id})
+}
+
+func (l *Lobby) Leave(ctx context.Context, id int) error {
+	return l.upsertEvent(ctx, lobby.PlayerLeave{ID: id})
+}
+
+func (l *Lobby) upsertEvent(ctx context.Context, e lobby.Event) error {
 	if err := upsertEvent(ctx, l.id, e); err != nil {
 		return err
 	}
@@ -25,6 +34,21 @@ func upsertEvent(ctx context.Context, lobbyID int, e lobby.Event) error {
 	if err != nil {
 		return err
 	}
-	_ = b
-	return io.EOF
+
+	_, err = db.From(ctx).ExecContext(ctx, `
+      INSERT INTO lobby_events (lobby_id, payload) VALUES (?, ?)
+   `, lobbyID, b)
+	return err
+}
+
+func (l *Lobby) apply(e lobby.Event) error {
+	switch e := e.(type) {
+	case lobby.PlayerJoin:
+		if !slices.Contains(l.Players, e.ID) {
+			l.Players = append(l.Players, e.ID)
+		}
+	case lobby.PlayerLeave:
+		l.Players = slices.DeleteFunc(l.Players, func(id int) bool { return id == e.ID })
+	}
+	return nil
 }
diff --git a/src/state/fsm/lobby/lobby_test.go b/src/state/fsm/lobby/lobby_test.go
index 9c443aa..4588fc8 100644
--- a/src/state/fsm/lobby/lobby_test.go
+++ b/src/state/fsm/lobby/lobby_test.go
@@ -7,9 +7,41 @@ import (
 )
 
 func TestOpen(t *testing.T) {
-	l, err := lobby.Open(lib.NewTestCtx(t), "id")
+	ctx := lib.NewTestCtx(t)
+
+	l, err := lobby.Open(ctx, "id")
 	if err != nil {
 		t.Fatal(err)
 	}
 	t.Logf("%+v", l)
+
+	if len(l.Players) != 0 {
+		t.Errorf("new lobby has players: %+v", l.Players)
+	}
+
+	if err := l.Join(ctx, 1); err != nil {
+		t.Fatal("failed to join:", err)
+	} else if len(l.Players) != 1 {
+		t.Errorf("wrong number of players after first join: %+v", l.Players)
+	}
+
+	if err := l.Leave(ctx, 1); err != nil {
+		t.Fatal("failed to join:", err)
+	} else if len(l.Players) != 0 {
+		t.Errorf("wrong number of players after only leaves: %+v", l.Players)
+	}
+
+	if err := l.Join(ctx, 1); err != nil {
+		t.Fatal("failed to join:", err)
+	} else if err := l.Join(ctx, 1); err != nil {
+		t.Fatal("failed to join redundant:", err)
+	} else if len(l.Players) != 1 {
+		t.Errorf("redundant join yielded wrong players: %+v", l.Players)
+	}
+
+	if err := l.Join(ctx, 2); err != nil {
+		t.Fatal("failed to second join:", err)
+	} else if len(l.Players) != 2 {
+		t.Errorf("second join yielded wrong players: %+v", l.Players)
+	}
 }
diff --git a/src/state/fsm/lobby/open.go b/src/state/fsm/lobby/open.go
index 13f25aa..834a32b 100644
--- a/src/state/fsm/lobby/open.go
+++ b/src/state/fsm/lobby/open.go
@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"gitea/price-is-wrong/src/lib/db"
 	lobby "gitea/price-is-wrong/src/state/fsm/lobby/internal"
-	"slices"
 )
 
 type Lobby struct {
@@ -61,7 +60,7 @@ func openID(ctx context.Context, id int) (*Lobby, error) {
 	rows, err := db.From(ctx).QueryContext(ctx, `
       SELECT payload
       FROM lobby_events
-      WHERE lobby_events.lobby_id=(SELECT id FROM lobbies WHERE name=?)
+      WHERE lobby_events.lobby_id=?
       ORDER BY id
    `, id)
 	if err != nil {
@@ -79,11 +78,8 @@ func openID(ctx context.Context, id int) (*Lobby, error) {
 		if err != nil {
 			return nil, fmt.Errorf("failed to parse event: %w", err)
 		}
-		switch e := event.(type) {
-		case lobby.PlayerJoin:
-			result.Players = append(result.Players, e.ID)
-		case lobby.PlayerLeave:
-			result.Players = slices.DeleteFunc(result.Players, func(id int) bool { return id == e.ID })
+		if err := result.apply(event); err != nil {
+			return nil, fmt.Errorf("failed to apply event %s: %w", b, err)
 		}
 	}
 
diff --git a/src/state/fsm/lobby/players.go b/src/state/fsm/lobby/players.go
deleted file mode 100644
index 73c348d..0000000
--- a/src/state/fsm/lobby/players.go
+++ /dev/null
@@ -1,14 +0,0 @@
-package lobby
-
-import (
-	"context"
-	lobby "gitea/price-is-wrong/src/state/fsm/lobby/internal"
-)
-
-func (l *Lobby) Join(ctx context.Context, id int) error {
-	return l.withEvent(ctx, lobby.PlayerJoin{ID: id})
-}
-
-func (l *Lobby) Leave(ctx context.Context, id int) error {
-	return l.withEvent(ctx, lobby.PlayerLeave{ID: id})
-}