Export and play Scenario

To play a scenario, save it into the map/setup_scenarios folder of a mod enabled in your playset. Most maps go into Paint a Galaxy's.

Play a Paint a Galaxy map Paint a Galaxy

1. Subscribe to the Paint a Galaxy mod on the Steam Workshop.
2. Use File → "Save into the Paint a Galaxy mod…". It saves into the mod's map/setup_scenarios folder, where the game looks for it. Steam may replace that folder when the mod updates, so keep another copy of your map somewhere safe.
3. In the Paradox launcher, enable Paint a Galaxy in your playset. If your map has reserved seats, enable the Reserved Spawns submod as well.
4. In Stellaris, start a new game. Your map appears as a galaxy size, under the name in the scenario's header. The status bar shows you the name when you save into the mod. Once you pick your map, the game doesn't ask for a galaxy shape.
5. Set AI Empires on the new-game screen no higher than the "safe AI empires" number in Galaxy Forge's Game setup. Above that, there are more empires than seats.

Give each map in the mod's folder its own Name on the Galaxy page. The game shows only one galaxy size per name.

What the mod does on day one and who starts where are on their own pages.

Play a plain scenario

A scenario made without the Paint a Galaxy checkbox has to sit in the map/setup_scenarios folder of a mod enabled in your playset. Your own mod has to deal with what goes wrong without Paint a Galaxy.