In BDSM, edgeplay is a subjective term for those types of activity (either sexual or mental manipulation) that may be considered to be challenging the conventional or traditional "S.S.C." (safe, sane and consensual) creed; if one is aware of the risks and consequences then the activity(ies) would be considered RACK (Risk-Aware Consensual Kink).
Edgeplay may involve the consequences of potential short or long term harm, or death, exemplified by activities such as breathplay (erotic asphyxiation), fire play, knife play and gunplay, as well as the potential increased risk of disease seroconverting when the opportunity of bodily fluid exchange is present, such as with cutting, bloodplay or barebacking.
The mind set of those involved in the session(s) constitutes what is edgeplay because knowledge of or experience with the activity or the partner(s) may dictate what and to what extent they will act. In the mid-1990s, the Living in Leather convention did not have panels on ageplay or scat because they were considered too extreme based on what people thought as acceptable activity if consensual by the parties involved. By 2000 they were part of what participants could potentially expect if part of their scene(s).