I believe GP was referring to the fact Steam itself is 32-bit only, with the singular exception of MacOS (last I checked, if this has recently changed, I apolog

I believe GP was referring to the fact Steam itself is 32-bit only, with the singular exception of MacOS (last I checked, if this has recently changed, I apologize). So even if your game is 64-bit, you still need 32-bit libraries and OS support to run the DRM. Sucks when either your OS doesn't support 32 bit (MacOS, OpenBSD), you don't want to add 32 bit multilib, or you're doing funky emulation on a non-x86 machine where you can only effectively emulate x86_64 (see: ppc64le). These are all niche situations (the last one almost facetiously so), but the point stands. I really wish valve would release a 64 bit client on Windows and Linux :/