Your longest marathon tabletop gaming session?

[Zatropia]

I used to play DnD v3.5 with four other people and then the DM, and I think we'd had times where the game lasted 12 hours. It was a bit rough, but we were a hugely roleplay heavy group, and the DM was great at thinking of great worldbuilding details and making up NPCs on the spot. We would spend like 20% of the time fighting things and the rest of the time talking to each other or exploring the world or talking to random townsfolk/animals/etc. So many detours. I miss it.

[Visitbox]

I played 50 matches of Yu-Gi-Oh in a row non-stop with a friend once, which honestly, isn't very impressive.

[Ryuondo]

I had a 3v1 Warhammer 40K game back during 5th edition that took like 7-8 hours to complete. I feel like it probably would have gone on longer now.