Sadly even pressed CDs have been known to rot[0][1]. Albeit it's not I tend to hear about with audio CDs because (presumably because there are usually other ways to acquire copies) however it is something that worries a lot of retro gamers like myself. It means that many of the Mega CD, Saturn, etc games (for example) have a potential life expectency.
For me though, scratched discs affect me more than disc rot. It can be a lottery sometimes when buying retro games because you can't always be sure just how well looked after the disc was (even when you have pictures and the item is marked as tested/working).
I feel we're already reaching a point where game preservation for older systems like Mega CD and PC Engine CD really need to have multiple rips that then weigh all the rips to try and correct for individual errors in each rip.
> even when you have pictures and the item is marked as tested/working
I bought a PlayStation 2 second hand a while ago to relive some memories and to play some of the games that I hadn’t yet played.
One of the games played perfectly well up until about 60% through the story and then there is a bad scratch on the disc at which point the game freezes.
I think most sellers of used games will only pop the disc in and see that it starts, if they even bother to test the game at all. That is reasonable of course — we can’t expect anyone to play through a whole game another time over just to see that the whole thing works as it should before they sell it for a couple of dollars. But yeah it’s a risk and it does suck a little bit.
Had a similar problem when buying a used copy of Metal Gear Solid 1 on the PS1, the game and both discs worked fine but if you died on the second disc while in story mode the game would lock up. Added a bit of extra difficulty at any rate!
If you're buying a used game you can be sure it isn't tested and is sold as is. Even if they say it's tested or guaranteed, that only means they're willing to give you a refund if anything is wrong.
I recently ripped (using a blueray drive) a half-dozen CD-R's I burned 18-20 years ago. All had been tucked away in a Logic case; all ripped fine ... except one, which had several visible mechanical dings (3 of 6 tracks lost).
Better than I'd hoped. I've had a handfull of newer CD-Rs go unreadable, for invisible reasons.
Are you referring to pressed or burned CDs? Or Both?