EXPcalibur guide

The mode fork happens once, before the match.

The uploaded artifact picks an engine before tick oneThe uploaded artifact picks an engine before tick oneUploaded artifactRunner reads the raw file once.Ordinary image → CLASSICOuter VM behavior feeds namedmeters and capped effects.Recognized wrapper → ABYSSOuter VM can request checked innerwork and temporary Drive.Same world: actions → combat → drops → picked-up EXPMode belongs to the upload, not to bytes later changed inside guest memory.

The runner reads the uploaded artifact, fixes CLASSIC or ABYSS, then starts the same outer VM and arena loop. The exact 32-byte choice is below.