I think of Antallos as a planet in the Battletech Universe where someone is always fighting over something. Usually smaller bands of pirates or mercenaries or treasure hunters fighting over Star League era resources left on the planet when the Star League collapsed. That makes it a great place for a map based campaign for multiple forces.
We've set our 3040 campaign in Port Krin the closest thing to a capital city on Antallos. I've divided the map into 74 or so neighborhoods and each faction is trying to take over neighborhoods in the city and build up businesses to help supplement their income to maintain their forces. The trick is that we are not only fighting each other for control of the city. Various NPC forces are also active in the city and player neighborhoods can even be raided by these NPC. We are 7 or so turns into our campaign and we have yet to fight each other outside of the starter scenario. Instead we have mostly been spreading out through NPC controlled neighborhoods fighting off other pirates and mercenaries.
Each of the four players in the campaign choose a force style based on their experience level. Myself and the other player who have over 20-30 years experience playing Battletech built Pirate forces. I call mine "The Scrap Dogs" and he calls his "The Blue Phantoms". We started with a lot less money than the other two players and we can only deal with the Black Market to buy supplies, mechs, and parts to repair our mechs. My daughter is playing an irregular mercenary force called "The Hunters of Horus". Mercenary forces can deal with the Black Market or buy supplies, mechs, and parts from Military suppliers located in the Inner Sanctum which is a non contestable area at this time in the campaign. My wife who has only played a few games of Battletech prior to this campaign choose to play a Draconis Combine force consisting mostly of units from The Legion of Vega who's background make them particularly suited for operating on a mostly pirate controlled planet. She can requisition supplies, parts, and even mechs from the DCMS for free but these request can be denied based on her rank. She can also deal with merchants from the Inner Sanctum and the Black Market to buys supplies like everyone else if she chooses. Each force can also buy influence among their available markets to make finding things easier and cheaper.
To kick off the campaign we had a four way battle set outside of the city of Port Krin where we all fought over Star League era technology that had been scattered across the desert by a drop ship that was attacked by pirates.
Immediately the Blue Phantoms and Scrap Dogs agreed not to fight each other and split the booty nearest our deployment zones. We planned to engage the others only to keep their heads down.
The Hunters of Horus and Legion of Vega however choose to fight it out causing some nasty damage to each other in the process. As such even though they won slightly more of the booty than the pirate forces they had to spend quite a lot of it just to replace and repair their damaged units.
Hunters of Horus mechs and tanks move through another part of the city defended by another mercenary company.
A Draconis Rommel tank is and two Legion of Vega mechs engage pirates.
Scrap Dogs engage mercenaries in a ruined section of Port Krin.
A combined force of Blue Phantoms and Scrap Dogs attack The Carrion Crows an NPC pirate force defending the Carrion Pit neighborhood.
The Draconis Legion of Vega Forces attempt to move into the North Slums of "The Lost" neighborhood only to be pushed back by The Lost Dogs an NPC pirate militia force defending that part of the city.
The Scrap Dogs and Blue Phantoms again fighting side by side against local forces. I believe this time to capture a neighborhood for the Phantoms.
The Hunters of Horus commander in the Black Knight fighting mercenaries.
At seven turns in we are starting to run out of room to avoid each other especially since we managed to deploy so close together. I'm about to start a series of special scenarios like the one we fought to kick off the campaign as well as adding some other elements. Once one of our forces secures Port Krin and becomes the new controller we will expand the campaign to the rest of the planet. I should be adding more frequent updates from here on.