Sections

The CHK format reference lists every section the editor knows, with a page for each. The editor decodes all of them into its own model, and re-encodes them when you change them, except VCOD, IVER and IVE2, which it only ever carries as bytes. Any section not in that list is one the editor does not know, and it is carried through untouched. Tools ▸ Check Map reports a section the game requires and the file lacks as an error.

What the game reads and what it skips#

Nine sections are read by editors and skipped by the game: ISOM, TILE and DD2 for terrain editing, and IVER, IVE2, IOWN, UPUS, SWNM and WAV as bookkeeping. The Save dialog can leave each group out, and Smallest that plays leaves out both. The map plays the same without them. What changes is what an editor can do with the file afterwards:

• Without ISOM, the isometric brush has nothing to paint with. The Repair plugin can rebuild the record from the tiles, and does a good job on terrain that was laid isometrically to begin with.
• Without TILE and DD2 , doodads are no longer objects. Their tiles are still in the terrain and their sprites are still in THG2, but an editor cannot pick one up or restore the ground beneath it.
• Without SWNM and WAV , switches lose their names and the Sound Editor its list; the triggers that use them are unaffected.
• IOWN, IVER, IVE2 and UPUS are StarEdit's own notes and cost nothing.

Stripping these is what map protectors and "map compressors" have always done. It is reversible only as far as the Repair plugin can reconstruct the record, so keep an unstripped copy of any map you are still working on.

Sections a map may not have#

ISOM, MASK, WAV , CRGB, SWNM, the CUWP slots and every settings table are optional, and the editor writes none of them into a file that had none: a map without a MASK section stays without one, rather than gaining an all-clear fog table it never had. A map with no MASK plays as fully fogged for every player, which is also how the editor shows it. A map with no ISOM cannot use the isometric brush until the record is rebuilt.