MRPG Hidden Doors
Hidden doors, collapsing floors, and other secret passages can be detected by those with a high Perception skill.
Mage Wars RPG
In Mage Wars RPG, a player must click on the hidden door to bring it to the attention of the other players, it will then be visible on their screens as well.
Mage Wars PnP
In the PnP game, the GM will inform the player or players who passed the perception-check that they have spotted a door, and they must then inform the other players(see MPNP Metagaming and Role Playing).