In PlayStation 2 (and other consoles, for what I could find), when you play Need For Speed: Most Wanted, if it finds that the memory card contains save data for Need For Speed: Underground 2, you receive an extra $10,000 at start in Career mode.
Is there any PlayStation 1 title that could read game data for another game and use it somehow? (I presume it would be to the player's advantage if so, but I'm interested in any kind of effect).
Best Answer
Metal Gear Solid at some point does this too, and Gran Turismo 2, if you got all licences in GT1 you can save up time in GT2 by most than half if I recall correctly.
There was an option in my old PC PSX emulator which allowed to copy save files from one memory card to another (since it made a dedicated card for every game), I saved all konami in one, all GT in another, and so on.
In PS2 playing Metal Gear Solid 3, there's a scene that I'm not sure it would pop if you didn't have Lament of Innocence on the same card, that I can't say for sure.