Gaming apparatus, e.g. an Electronic Gaming Machine (EGM) (1), includes a controller (2) for implementing e.g. a slot-machine game, a poker game or the like. The EGM (1) displays a gaming image on a display (5), e.g. virtual symbol reels or card hands, and receives player instructions via an input (6) or the like, e.g. to spin the reels or manage the cards. The EGM (1) includes a guarantee feature in which an event is guaranteed to trigger if a monitored event (e.g. of the same type as the guaranteed event) does not occur within a set amount of gameplay. A guarantee indicator (9), e.g. a numerical countdown or gauge, indicates the remaining amount of gameplay required before the guarantee feature triggers. The monitored and/or guaranteed event may be a win event or a feature event, e.g. the triggering of a bonus round, free game or the like.