Age play is the term for consenting adults who roleplay in some way pertaining to age. Sometimes this is "infantilism", which is adults acting as babies. There are all ages.. this can also include schoolgirl or schoolboy with headmaster or headmistress, and every conceivable age in between. Consensuality is key, and let me stress again this is ADULTS - it has nothing whatsoever to do with anyone under the age of consenting adult.

When your so pissed off from losing multiple amount of games that you play worse and worse till your so pissed you begin leaning over your keyboard screaming over every little mistake you make and complaining about gaming imbalances

(Common in Starcraft II)

Usually sexual roleplaying involving Daddy/daughter, Daddy/son, Mother/son, Mother/daughter, Police/arrested, Teacher/student, Doctor/nurse, Doctor/patient, Uncle/niece, etc. The main stipulation is that one person is either older or playing older than the second person, or the submissive person is younger or playing younger than the dominant. Both people involved are ALWAYS adults.

Ageplay is when you act or behave in a manner that isn't your biological age, mostly when one acts younger than they really are, often considered by some as a form of role-play however many of us within this lifestyle this is not the case and often insulting because this is who and what we all are we feel that we don’t take on a role, however those not involved within ageplay do not understand this and see what we do as taking on a role for example I am not a biological Daddy although I am a Daddy to my ab girl so outsiders see this as me taking on the role of a Daddy.
Anyone who is Ab, Little, Middle or Teen ARE ageplayers you cannot be Ab, Little, Middle or Teen without ageplay no matter what anyone tells you it is impossible to be Ab, Little, Middle or Teen without ageplay, we are all ageplayers and each and every one of us should embrace this as it is who and what we all are and you should never be offended or embarrassed to be an ageplayer.
There are 2 types of ageplay.

Regression – where the ageplayer needs to be regressed to a younger age or "little space" regression is when your mind has to go back to a different age, it physically reverts to a younger age, when this happens the ageplayer does not think like a grown up only the age they revert to.

Non regression – where the ageplayer is always in a younger frame of mind be it ab, little, middle or teen and doesn’t need regressing.

A person who gets sexually aroused by Dating someone older than them who takes a role of a caregiver or dom

Also an Ageplayer is a person who acts a younger age than their normal to please the dom or caregiver and be totally submissive to them

roleplay that involves one or more parties not acting their age, usually in a regressive manner.