We investigated the effects of response effort on the use of mands during functional communication training (FCT) in a participant with autism. The number of links in a picture exchange response chain determined two levels of response effort. Each level was paired with a fixed ratio (FR3) schedule of reinforcement for aggression in a reversal design. Responding to either schedule produced access to a preferred item. The participant opted for the low effort mand while aggression decreased significantly. However, the high effort mand did not compete with the FR3 schedule for aggression. Results are discussed in terms of response effort within a response chain of a picture exchange system and competing ratio schedules for problem behavior during mand training.