On a 32-bit linux installation (I'm running Debian 8 and the version of Steam in the Debian non-free repository), Steam will happily download games (in my case, Cities: Skylines) which only have 64-bit executables. The only indication that this won't work is the somewhat cryptic error "Failed to start game (missing executable)" when attempting to launch the game.
Ideally, when running under a 32-bit kernel, Steam would refuse to download 64-bit-only games, or warn that they won't run on the current system when the user attempts to do so.
On a 32-bit linux installation (I'm running Debian 8 and the version of Steam in the Debian non-free repository), Steam will happily download games (in my case, Cities: Skylines) which only have 64-bit executables. The only indication that this won't work is the somewhat cryptic error "Failed to start game (missing executable)" when attempting to launch the game.
Ideally, when running under a 32-bit kernel, Steam would refuse to download 64-bit-only games, or warn that they won't run on the current system when the user attempts to do so.