This is another mech-based campaign idea. I've been on kind of a mech kick since rewatching Evangelion with my wife and have been thinking about various mech campaigns. This is one I came up with a while ago and have thought about adapting to Traveller or other systems (maybe even Lancer) at various points. If I ever ran this I'm not sure what rules I'd use since the current Battletech RPG looks kinda naff.
If you don't know anything about the Battletech setting I recommend watching the intro cinematic to the video game. "Some Indian" who writes Straits of Anian I think correctly identified it as doing an excellent job telling the history of the setting using only visuals.
An AWOL Kurita mech waits in ambush on the devastated planet of Alexandria
Alexandria was once a jewel of the Star League. A high population world nearly entirely covered with urban environments and manufacturing zones, it was home to several mech factories and produced many of the designs still seen in the Succession Wars. It's position along the central spine of the Inner Sphere also made it strategically important for maintaining hegemony over space.
Unfortunately, when the Star League disbanded it ended up wedged between houses Steiner and Kurita - both known for their bellicose militarism. During the first two Succession Wars the planet was pounded with everything each house had at its disposal, including notably treaty-defying orbital bombardment. Between the wars the two sides would raid across their borders and often the target was Alexandria. Now most of the planet is rubble and few have any reason to visit the dying world.
The current inhabitants live a meager life in the ruins. They run in factions that are little more than heavily armed street gangs. The only way to eek out a living, it seems, is by squabbling over the ruins, the planet's atmosphere likely incapable of supporting crops. Somewhat recently, a group of pirates with a company of mechs and even more conventional fighting vehicles landed on the planet and has been attempting to use it as a pirate port.
You are members of the 2nd Legion of Vega, stationed a few jumps away from Alexandria. A sink for dishonorable warriors, washouts, burnouts, and even political prisoners, the Legion of Vega is noted for its unconventional tactics, poor morale, and miserable duty assignments. Despite being assigned to this forlorn hope, it looks like your luck is about to change. A member of your company has heard a rumor that one of the factories on Alexandria would need only minor repairs to become operational again, and may even have a huge store of Lostech!
Luckily for you discipline in the 2nd Legion is so lax that making off with a drop ship and hitching a ride on a jumpship to Alexandria seems to have been met with a very muted response. If you get the factory working, maybe they'll forgive you for going AWOL because of the wealth you'll bring to House Kurita. If not, you can always be the petty tyrant of your own planet.
Unfortunately there seems to be a problem. Someone is occupying the factory... and its the pirates...