Ageplay is a type of sexual roleplaying or BDSM in which a person pretends to be an infant, child or adolescent. Technically, infantilism is a subset of ageplay.

The dominant plays the role of teacher, doctor, parent, etc. Ageplay can also be bratplay in which the "child" is disobedient and bratty, and puts up verbal or physical resistance. (In such play, a safeword is even more important.)

Ageplay is often regarded as edgeplay, because it reminds people of real-life incest or pedophilia. Proponents point out that ageplay is a consensual fantasy played out by adults.

The appeal of ageplay, like other forms of submission, is in giving up responsibility, allowing oneself to be vulnerable and to give and receive affection freely.

Some ageplay is purely regressive; while the person is in role, nothing that wouldn't happen with a real minor occurs. Other includes sex or sexual play, such as erotic spanking, and incest or pedophilia fantasies.