Abstract: A first set of symbols associated with respective positions of reels may be selected as an outcome event of a reel-based game. The first set of symbols may include one or more trigger symbols. It may be determined that (i) the outcome event does not include a primary trigger event that causes execution of a bonus feature, and/or (ii) the outcome event includes a secondary trigger event that causes replacement of the one or more trigger symbols. Possibly in response to determining that the outcome event includes the secondary trigger event, the one or more trigger symbols may be replaced with replacement symbols to form a second set of symbols. A bonus payout amount associated with the second set of symbols may be determined. An indication of the bonus payout amount may be provided to the client machine.