A new sandbox milsim RTT with modding support — the ArmA of tactics games?

ArmA players don't love ArmA because it's a shooter. They love it because it's a platform: every soldier simulated, firefights that emerge instead of following a script, and a modding scene that eventually built entirely new games on top of it (DayZ started as an ArmA mod).

I'm building the same idea, but for real-time tactics.

Open Ground

A small-unit milsim RTT in early development. You command squads — not one soldier — across real-time battles where every man is simulated: line of sight, suppression, wounds, morale, prisoners. Pinned men crawl to cover, medics drag out the wounded, broken squads fall back on their own. Nothing is scripted; the battle writes itself.

The sandbox part

Skirmishes are configurable: pick the terrain, the forces, the era. The environment plays along — walls crumble, craters scar the ground, wrecks become cover, and the field remembers every casualty for the whole battle. It's less "beat the mission" and more "set up a situation and watch what happens."

The modding part — and this is the point

Open Ground is data-driven by construction: scenarios, factions, weapons, eras — they're all plain files. There's no hidden engine tier where "real content" lives and a locked-down tier where modders get scraps. The game itself is built out of the same folders and JSON a modder would touch. Different eras — modern, Vietnam, WWII — swap in as content packs on the same simulation core.

That's the deliberate design: a milsim platform, not a game with modding bolted on later. ArmA earned its decade-long life that way — an editor and open files turned one game into a genre. I'd rather have ten modders making weird scenarios than a thousand players who finish the campaign and leave.

Where it actually stands

Pre-alpha. The sim runs, battles are playable, the editor exists in-game, and the content files are the real format — but there's no formal modkit release or Steam page yet. What exists today is the channel: raw, unedited sessions (jungle fights where squads break contact on their own, night assaults, a 30-minute uncut battle where men treat their own wounds). If the ArmA pitch sounds like your thing, that's the best place to see whether the claim holds.

I'm building in the lineage of Close Combat, Combat Mission and Men of War — and taking the sandbox lesson from ArmA.

Follow the build: YouTube (new footage weekly — Vietnam goes public Friday) · Discord — feature requests actually shape the build · Ko-fi — the $100 goal funds the Steam Early Access page · openground.intrane.fr