We use the term "age-gate" to refer to the interstitial pages presented to players when browsing the Steam Store or Community when the content they are about to view may surprise them. Below describes the couple of different triggers for these age-gates and different presentations.

Content Preferences

Players can define their store content preferences to filter out or allow in certain kinds of content, such as violence or nudity. If a player is visiting your store page and if your product has content descriptors that the user has indicated they do not want to see (including defaults), they will be presented with a warning. This is keyed off the settings you entered in filling out the mature content survey while setting up your store page.

These warning pages will let the player know that the content they are about to view is different from the preferences they have previously specified (or the defaults that Steam has).

Regional Rating Board Settings

Players may also encounter an age-gate if you enabled age-gates while entering in ratings from regional rating boards such as ESRB or PEGI. There is a checkbox in the same place you enter those rating levels and descriptors, which will enable the age-gate.