‘the walking dead: all out war’
Technically  does not have 3+ player scenarios, but it shouldn’t be too hard to invent something.

Killteam does have options for 2+ player scenarios in the core rules.

‘Mythic Battles: Pantheon’ definitely has 2+ player scenarios, but it isn’t available at retail so might be tricky.

Bolt-Action uses order tokens/dice for activation, which makes me think that adding an extra player simply involves adding their order dice to the bag.

Blood&Plunder definitely has plenty of options for 2+player scenarios as you can combine naval battles with land based skirmish.

Any wargame can be structured for multi player.

We used to have great fun with huge multi player Vietnam games, and Wild West gunfight games work perfectly.

Rangers of Shadow Deep is designed for 1-4 players (plus one if someone wants to act as the person who runs the monsters). Lots of fun, very narrative.

I think just about ANY game can be multiplayer (even ones designed for 2 players), all you need to do is dedicate “parts” of each force to different players.

For BA you don’t even need a third (or more) sets of dedicated dice. All you need to do is dedicate squads etc to individual players (and then let the players one that side debate who NEEDS that activation first, that’s part of the fun), a multiplayer game can be about co-operating as much as fighting each other…

For our historical refights (that can have up to 5 players a side for the really big battles), we just assign players command of brigades and/or divisions and they fight the player opposite. Sometimes we have a bit of a hold up if their flanks start to interact with another player (and you have to wait a bit until they are “free” to resolve your bit), but that doesn’t tend to hold up the game that much. But basically in a YGIG game, you’ve got simultaneous “battles” being fought side by side that might “clip” into each other, but as a whole the game usually has the ALL players engaged most of the time.

Sure sure.. ANY game CAN be multiplayer. But that doesn’t mean its any good. And normally, one player invariably gets beat up on by the other 2. I have tried many of the games listed here in a 3 way.. none have been fully satisfactory. Some, the play turns just take too long (SAGA).. and some, its obvious it was never intended to handle more than binary play (KillTeam).  Having said that the games that use random draw and quick turns (Bolt Action, B&P etc) work best of those listed as long as you play low point games.  A game I might suggest however, is Fistful of Lead. Its wild west (and other themes) and has been designed from the ground up with multiplayer in mind. My group has always had a blast playing 3, 6, even 15 people (15 does get a little slow tho). https://wiley-games.myshopify.com/