Text entry is a very conservative part of HCI because new text entry techniques often require retraining the users. To minimize the cost of learning we experimented with a joker key. It is a key that can be pressed when the user does not know how to enter a character. The text entry system replaces the joker characters with best guesses for the intended characters. As learning progresses the joker character is needed less frequently. Our data in the context of the MessagEase text entry method shows that the joker key improves the initial performance. Our results also include the first longitudinal study on beginner performance with MessagEase.