LARP is a game of improvisation. No-one gives you lines to read and there is no computer or pen-and paper system recording how many hit points you have left. You are trusted to keep track of what your characters does and does not know, how many hit points they currently have and what their perks can do among other things. In return, you are expected to trust your fellow players to manage their characters in the same way. Betraying this trust by granting your character knowledge that you acquired out-of-character, forging your stats or hit points, or using abilities that your character should not be able to is considered cheating. Such offenses can result in removal from the event and club.
While the trust-based system asks that you do not cheat, it also asks that you are prepared to grant your fellow players the benefit of the doubt when you are lead to believe that they may be misusing or misunderstanding the rules. This may occur, for example, when you attempt to use one of your character’s abilities on another character and they appear to ignore the effect. In events such as these, you are asked to avoid confrontation. While you may wish to straighten out what just occurred, going out-of-character to do this is a sure way to ruin the immersion and enjoyment of everyone involved. Instead, consider that the other player may be making use of a rule that allows them to negate the effects of what you attempted upon them and, above all else, just keep playing.
If you truly believe that a player may be abusing the trust-based system, intentionally or otherwise, you are invited to inform a member of the referee team whenever you have a quiet moment rather than confronting the player yourself. Finally, it is not just in the face of doubt that you are asked to remain in-character. Arcadia is a 24/7 event. This means that you are expected to be portraying your character all day throughout the event. This is not enforced, of course, and certain areas are made available for going out-of-character for various reasons but outside those areas you should try to stay in character as much as possible.
LARP can get intense when you are fully immersed in your character and they are experiencing something traumatic. If the roleplay ever gets too much or takes a direction you are uncomfortable with it is fully acceptable to break character and say safeword. This allows the other players roleplaying with you to cease the roleplay and make sure that everyone is ok.
Mobile phones are also discouraged in in-character areas as they ruin the immersion of other players, unless they are disguised and cannot be spotted by anyone. For example some players may keep character sheets and rule references on their phones but the phones themselves must be disguised to look like an in-character prop. Mobile phones can be used in out-of-character areas but be warned there is no where to charge your phones at Arcadia LARP so they may run out of battery very fast!