[Fyron]

That is why, in addition to disabling surrender, you need a house rule such as this:

Surrender is disallowed. Therefore, gifting all of your planets, ships, etc. to another empire, which is an attempt to subvert this rule, is also disallowed. If you happen to see other players do this in the game, tell me, and I will investigate the situation. If this rule has been broken, I will upload an old turn to prevent it from happening, and I will consider kicking the offending players from the game.