It has been a while, but PlayStation is getting back to backward compatibility.
As a part of today's PlayStation 5 deep dive -- and it's a deep enough dive to blow out your eardrums if you don't have proper scuba equipment -- PlayStation master architect Mark Cerny confirmed that the new console will be able to play PS4 games at launch. Most of them anyway.
As Cerny explains, the PS5 "incorporates any differences in the previous console's logic into the new console's custom chips." That means that "the logic and features sets that PS4 games rely on is still available in backward compatibility modes." Cerny says this is the crux for backward compatibility on PS5, as opposed to adding the PS4 chipset into the PS5 chip which is "extremely expensive."
The result is that most PS4 titles will be playable on PS5 at launch. Cerny specifically mentions that Sony looked at the top 100 most-played PS4 games and "almost all of them" will be backward compatible. However, every title has to be individually tested because some "game code just can't handle it."
