Draw a mission's battle site on a fixed 38×38 grid. Load a mission and one of its sites (or start a new one), pick a tool, and click/drag on the grid. +x is right, +y is up — you're looking down at the table. There is no zero tile: the centre gridline (0,0) is where the four central tiles meet.

• Terrain / Region — click-drag a rectangle.
• Object / Enemy / Key Point / Trap — click a single tile. Enemies use the mission's stat-block names.
• Select shows a marker's details; Erase removes the top marker on a tile.
• Save to mission writes the site back into the mission's run sheet; Export .md gives the importer-grammar block.