It is against the rules for someone to play someone else's account, for any reason, without prior notification of admin. Even then, Evony allows limited account-sitting with admin approval, but not unlimited account-sharing.

In other words, if you are expecting to be out of town and want your wife to play your account for you, that's fine if you let them know. Going on vacation and want your VH to watch over things? Again, fine if you let them know.

What Evony does NOT allow is the practice of sharing account information with members of your alliance so that nobody is ever really offline. They jump onto each other's accounts to defend, attack, etc. If you trust each other that much, why not share cell numbers so you can text each other when needed? Or make contact via skype/msn/aim? There's nothing wrong with that...They just don't want everyone jumping on and off each other's accounts as that is unfair gameplay and goes against the spirit of the game.

note: copy/paste from a FB statement with a few words changed. (Like "we" changed to "they," since I'm not an Evony rep)