I understand that this game is about political intrigue, backstabbing and deals, but should an alliance between Sol and the Lazax even be made possible? From the background story, something like this shouldn't even be possible.
What do you guys think? I'm thinking about making it a house rule. Didn't see it proscribed in the rules.
Evidently you are not familiar with the old axiom "keep your friends close and your enemies closer." =P
It may seem counterintuitive for the Lazax to ally with Sol, and surely such an alliance would be fraught with mistrust, thematically, but there are still reasons why it might happen. Sol might offer Lazax the chance to surrender. Lazax might accept in an effort to retain at least some measure of their former glory (or as a stalling tactic while they look for a way to turn the tables.)
In Dune, forming an alliance with someone didn't always mean you liked them, it just meant you needed something from them. In Rex there's even less reason to trust your allies if you play with the optional Betrayal cards. You can make a house rule against it if you want, but in my opinion there's absolutely no reason to do so, either mechanically or thematically.
After all, remember that they shouldn't be able to ally with Hacan either, and that there are formal declarations of war between them and the Jol-Nar and Letnev, and between Sol and Letnev, Sol and Jol-Nar, and, if I'm not mistaken, Letnev and Xxcha.
For one reason or another, basically nobody should be able to ally with anyone except possibly the Hacan or Xxcha, but one funny thing about war is that when you have an isolated theater, all sorts of surprising arrangements tend to emerge (especially when there are so many factions vying for control).
@Steve-O: I am familiar with that axiom. I just prefer another axiom: "The only time my enemy would get close to me is when I've sunk a dagger into his heart."
I am not too familiar with the mythology that is TI, having acquired both games rather recently. Can anyone get me up to speed?