Most disappointments in this category are not about condition. They are about a game that will not run on the machine the buyer owns, or a case that turned out to be emptier than it looked.
Ask these, in this order
"Can you show the spine?" Region, platform and edition usually print there.
"Can you boot it?" Thirty seconds of the game running answers more than any description.
"What is in the case?" Manual, inserts, the original disc rather than a loose one. Ask for the case open to the camera.
"Does it save?" For older cartridges, this is the battery question, and the honest answer may be "I have not tested it".
The playing surface
Ask for the disc tilted into the light. Scratches that matter show that way; a flat shot shows a clean-looking disc either way.
Sealed items
Treat a seal as a description, not a proof. Ask what the seller knows about where it came from and how long they have had it. A seller who answers plainly is worth more than one who assures you.
Authentication of a sealed item is not something a video call can settle. If that matters to you at the price you are bidding, it is a reason to bid less or not at all.
If it arrives and does not work
A game sold as working that does not boot, or a region that was not as described, is a not-as-described claim. Buyer protection covers it for seven days from delivery, and the store has a window to put it right before Metzee steps in.
Questions people ask
What is disc rot?
Degradation of the disc layer itself, which shows as small marks or a hazy patch. Ask for the surface tilted into the light.
Is a loose cartridge worth buying?
Often, at loose prices. Problems start when loose is described as complete.
Can I ask for a game to be tested mid-show?
Yes. Sellers who have a console on the bench expect it. How bidding works.
More: packing games, describing condition.