I'm testing one of the games on ubuntu 14.04 and when I double click the .deb all I get is a window telling me:

Wrong Architecture: 'i386'

There are absolutely no instructions telling me how to proceed and the classic solution of installing ia32-libs doesn't work anymore. Since I'm pretty sure almost every machine now uses a 64 bits OS, there should be some guidance here about getting this games to work, otherwise, is just very annoying to get stuck for something that silly

I think the simple answer is: Don't...

For simplicity the OS is either 32bit or 64bit, and all programs follow the same rules. It's more efficient that way.

The biggest reason of this is probably that most software that's put on Linux is usually free and/or open source, so you just compile it for your architecture. The problem with games is they don't come with sources usually. And if they did, you'd have to have all the appropriate libraries for it to compile right; Assuming the sources don't have problems for some reason (like bad paths for includes which requires you to fix it yourself).

edit: i wonder if my comment is wrong based on what i'm reading below. If it is, disregard...

What game are you trying to install? Also check if ia32-libs is already installed and check if your system meets the requirements for hardware and installed packages.

The game was Duke Nukem 3D, and the solution in ubuntu, gnomeubuntu and probably all other ubuntu variants, was that you have to run a command on 64 bits systems:

dpkg --add-architecture i386

and only then it allowed me to install it. However, I fell kind of annoyed about this kind of things, cause even though you can google the solution, this things should work just out of the box, and I blame ubuntu for that, so I switched to Mint, and there it indeed worked just fine automatically.

About the ia32 libs, that's for old versions of ubuntu. There were a couple of pages suggesting you to install this and that but it didn't work.

Even when they run, old games are often dependent on 32 bits versions of libraries in order to run without linking errors.

When in the package database, you can usually install those by adding ':i386' after the library name when running apt-get install.

For example, here's what I had to do to get Spaz running when I got it at the humble store:

http://www.spacepiratesandzombies.com/forums/viewtopic.php?f=15&t=4078