diff --git a/game.go b/game.go
index bf3b84b..5ecc63c 100644
--- a/game.go
+++ b/game.go
@@ -16,16 +16,48 @@ import (
 // An action is a request to change the game state.
 type action struct {
 	Action string    `json:"action"`
-	Param  string    `json:"param"`
 	Player player.ID `json:"-"`
 }
 
+func applyAction(g *game.Match, a action) error {
+	switch a.Action {
+	case "quit":
+		return g.Concede(a.Player)
+	case "across", "self":
+		if err := g.Shoot(a.Player, a.Action == "self"); err != nil {
+			return err
+		}
+		if g.RoundWinner() != nil {
+			return errRoundEnded
+		}
+		return nil
+	case "0":
+		return g.Apply(a.Player, 0)
+	case "1":
+		return g.Apply(a.Player, 1)
+	case "2":
+		return g.Apply(a.Player, 2)
+	case "3":
+		return g.Apply(a.Player, 3)
+	case "4":
+		return g.Apply(a.Player, 4)
+	case "5":
+		return g.Apply(a.Player, 5)
+	case "6":
+		return g.Apply(a.Player, 6)
+	case "7":
+		return g.Apply(a.Player, 7)
+	default:
+		return errWeirdAction
+	}
+}
+
 // gameActor is an actor that updates a game's state and relays changes to all
 // observers.
 func gameActor(ctx context.Context, g *game.Match, dealer, chall person, join <-chan person) {
 	// Games should generally be on the order of minutes. A four hour game is
 	// definitely expired.
-	ctx, stop := context.WithTimeoutCause(ctx, 4*time.Hour, errGameExpired)
+	ctx, stop := context.WithTimeoutCause(ctx, 4*time.Hour, errMatchExpired)
 	defer stop()
 	var obs []person
 	actions := make(chan action, 2)
@@ -51,9 +83,27 @@ func gameActor(ctx context.Context, g *game.Match, dealer, chall person, join <-
 			// observer when they disconnect
 			p.conn.CloseRead(ctx)
 		case a := <-actions:
-			// TODO(zeph): transform the action into a game state change
-			slog.DebugContext(ctx, "got action", "from", a.Player, "action", a)
-			broadcast(ctx, g, dealer, chall, obs)
+			slog.DebugContext(ctx, "got action", "from", a.Player, "action", a.Action)
+			err := applyAction(g, a)
+			switch err {
+			case nil:
+				broadcast(ctx, g, dealer, chall, obs)
+			case errRoundEnded:
+				broadcast(ctx, g, dealer, chall, obs)
+				if g.MatchWinner() != nil {
+					gameOver(ctx, dealer, chall, obs)
+					// TODO(zeph): server needs to know the players are gone
+					return
+				}
+				g.NextRound()
+				broadcast(ctx, g, dealer, chall, obs)
+				// TODO(zeph): broadcast shell counts?
+			case game.ErrWrongTurn: // do nothing
+			case errWeirdAction:
+				slog.WarnContext(ctx, "nonsense action", "from", a.Player, "action", a.Action)
+			default:
+				slog.ErrorContext(ctx, "action caused a mystery error", "from", a.Player, "action", a.Action, "err", err.Error())
+			}
 		}
 	}
 }
@@ -98,4 +148,18 @@ func broadcast(ctx context.Context, g *game.Match, dealer, chall person, obs []p
 	}
 }
 
-var errGameExpired = errors.New("there is a time limit on games please")
+func gameOver(ctx context.Context, dealer, chall person, obs []person) {
+	// TODO(zeph): need to communicate to the server that these have gone away
+	go dealer.conn.Close(websocket.StatusNormalClosure, "match ended")
+	go chall.conn.Close(websocket.StatusNormalClosure, "match ended")
+	for _, p := range obs {
+		c := p.conn
+		go c.Close(websocket.StatusNormalClosure, "match ended")
+	}
+}
+
+var (
+	errRoundEnded   = errors.New("someone h*ckin died")
+	errWeirdAction  = errors.New("unknown action")
+	errMatchExpired = errors.New("there is a time limit on matches please")
+)