Prism
Explorer
We have played one campaign to 20th+ level but it has taken nearly 30 years of real time to get there. When we started it we played it every week but in later years it has kind of become our backdrop game which we play 3-4 times a year, while we play much lower level stuff weekly. The characters are not optimized builds though - very organic - especially since we have changed system a few times. We are currently using a system called Microscope to play most of it but we break into D&D (5th at the moment) from time to time for the big encounters. Examples of those at this level are; restoring Lantan post spellplague in the forgotten realms, exploring Vecna's tower original tower for secrets about Asmodeus in Greyhawk, and most recently assassinating Bel, ruler of the first layer of Hell (Zariel now owes us a favour)
High level play is great fun but only from time to time
High level play is great fun but only from time to time