From Cossacks 3 Wiki
Cossacks 3 shipped with an editor by default. However, both tools are undocumented and the version accessed through the game's main menu is largely non-functional at the present.
Tips for using the editor
- Courtesy EbelAngel
- To launch the actual map editor, don't launch it from the Cossacks 3 main menu.
- Instead, open the Steam Library and right-click on Cossacks 3, then select Launch Game Editor.
- The default map size is 256. It can be increased from 192 to 1024 (square only).
- The environment tools allow for snowing.
- To place objects or units, first add players under Advanced→Players, then use the Tool Palette under Layer→Players (Control+Alt+U) to select the player and then the item you want to place.
- To manipulate terrain, select Layer→Terrain (Control+Alt+T), select the brush/factor and then the operation to perform with it.
- To add buildings, change the player race: Go to Advanced→Players→Player Race→Select Buildings, then return to the Tool palette (Control+Alt+U) to place them.
- To disable/enable Peace Time hit Control+W
- To Disable/enable Fog Of War hit Control+F