We play with four people using these adjustments:
- All three zones have to be burned.
- You may attack only one opponent at a time.
If you have any suggestions let me know.

I suggest that all resources should be shared between cooperating players.

We usually don't play in teams; it's more of free for all.

What about being able to place your units also in your teammate's capital (paying the standard cost plus the full loyalty cost)?