We breathe, they hunger.

After a lot of hard work, OSSA is finally live!

This micro-wargame was built from the ground up to fuse rules and theme perfectly, every mechanic is diegetic, every interaction represents the Dead pushing toward the Living.

If you enjoy zombie/undead stories, you’ll recognize the inspirations: temporary holdouts, improvised fortresses, contaminated survivors hiding their infection, morale breaking as positions collapse… OSSA captures all of this using nothing but a domino set and a grid.

Everything in the rules exists because it makes sense on the board:

• Build a Bastion? → You literally stack tiles to form high ground.
• A flank collapses? → Secure Zones flip and vanish.
• Someone was “infected”? → That blank half slips into a fortified area and becomes a new spawn point.

OSSA looks like the battle it simulates.

On balance

The grid you get is the result of hundreds of playtests. This size creates the fairest duel between the Skull and the Shield.

But you can tweak difficulty instantly:

• Dead advantage: remove 1 row
• Keeper advantage: add 1 row

Tiny changes create huge shifts in pressure.

Thank you so much for trying OSSA. It’s small, sharp, and brutal, exactly what I aimed for.

Have fun, and hold the line!

https://carta-mundus.itch.io/ossa

Mauricio/Cartamundus