Ubuntu Patching Heroes of Might and Magic 3

1) wget ftp://mirrors.dotsrc.org/lokigames/patches/heroes3/heroes3-1.3.1-x86.run
2) (wait for download to finish)
3) sudo su
4) (enter your password)
5) export _POSIX2_VERSION=199209
6) sh heroes3-1.3.1-x86.run
7) (enter the game directory when prompted)

Congratulations, you did it!
If you got an error stating checksums, make sure that you ran sudo su, and then the export command.