[2023] MOVED: questions about doors/ gates

The detection system will listen to whoever made it- If one of your friends made it, and set it to respond to 'Allies', and you aren't an ally, then yeah, it won't open.

When you place, for example, a motion sensor, in it's interface there are four options- "Target Self", "Target Allies", "Target Strangers", and "Target Zombies". Since your friend didn't enable "Target Strangers", It can't target you- Despite being partied before, you're not in a party now.