Glassware
Rocks / Old Fashioned
The short, heavy-based tumbler spirit-forward drinks are served over ice in. Capacity is to the brim; a drink is poured well short of it.

Whiskey Tumbler MET 176273.jpg — New England Glass Company
CC0 · Cropped, white-balanced, graded and re-encoded to WebP by eXir.
CC0 · Cropped, white-balanced, graded and re-encoded to WebP by eXir.
An empty heavy-based tumbler in smoke-grey glass, straight-sided, photographed against a pale ground
Capacity
To the brim300 ml
cubed ice displaces130 ml
block ice displaces130 ml
crushed ice displaces165 ml
Solid ice only — the liquid fills the gaps between pieces, so what has to be subtracted from the glass is the ice itself. Cubed assumes six to eight tray cubes near 2.5 cm; block assumes one 5 cm cube, which is why the two land in the same place from opposite directions. Crushed packs tighter and leaves less room.
Every drink below was checked against this figure at build time. A recipe that does not fit its stated vessel fails the build rather than shipping.