Reputation mechanics

[alpaca]

There's a very good way to break alliances without getting a reputation hit : offer to trade maps for maps with your "ally" turn after turn.

They might agree the first few times, but eventually they'll call it quits (either as a hardcoded way to prevent a diplomatic XP exploit, or because the AI sees a prelude to an invasion in you wanting to have their up-to-date maps)

Gosh we're two filthy power-gamers. Replacing an exploit with another exploit