A friend and I discussed this yesterday. Not exactly this but how it would be useful to just flat out give a unit/building to an ally. Such as an extra MCV if their Conyard was destroyed.

Sounds even better than the controversial #2583.

I’ve been looking for a game that supports this (Option 3) for a long time, and would find it awesome if you could implement it!

xanax asked me to tell my story why I want this game mode:

My motivation is this: I want to have a quick round of gaming with colleagues, where we do not have to wait for everyone to be there from the start. So two or more start a game, and the others join later at a side of their choosing. Also, it might be funnily confusing when two players try to control the same unit :-)

I guess the late joining would be a separate step, and depending on how the network code works (i.e. whether you can transfer the game state at a later point) this might or might not be possible. But I want it :-)

A third party mod could implement this by creating a new https://github.com/OpenRA/OpenRA/blob/master/OpenRA.Game/Traits/ValidateOrder.cs trait that allows multiple players to order the same units, and then tweak the lobby UI and game-start traits to give matching behaviour there.

This is a really specific use case that introduces additional complexity to the already busy lobby UI, so I think i'll call this one as out of scope for our default mods.