Within the Half-Life game folder was this map,
dm_office.bsp, a 2-player map resembling a small office complex. This was unexpected because the Dreamcast port had no plans for multiplayer. The map was later reused, with some minor changes, in the PlayStation 2 port's "Head to Head" deathmatch mode.
dm_office.bspis a one-floor map made of several office rooms, with lots of interconnection through hallways. The textures and prefab objects are also shared with Chapter 4 "Office Complex" from the single-player version - couches, file cabinets, desks, etc. make an appearance, as well as the wood-paneled walls, green carpet and checkerboard floors. The map is very small and intended for 2-3 players. The only weapons available are the shotgun and assault rifle (no grenades), plus the default crowbar and pistol.
The original version of this map, as found on the disc, included a number of embedded textures that also existed as exact duplicates in
halflife.wad. This version has been edited to remove the redundant textures, trimming ~225kb off the filesize.