How to Emulate the PS3 on a Steam Deck With RPCS3
Want to go back to the late aughts/early 2010s and relive the PS3 glory days on your Steam Deck? You can do it with the help of RPCS3, a PS3 emulator that can run all your PS3 favorites. Our guide will show you how to install RPCS3 via EmuDeck and how to get the emulator up and running.
Source: howtogeek.com