1 Quercus: I know a way we can escape into another universe.
2 Spanners: Quercus, that’s great!
3 Iki Piki: What do we need to do?
4 Quercus: Into the universe of our imagination! We play Dungeons & Dragons!
4 Serron: Because this universe wasn’t nerdy enough.

In the past 50 years we've had 5 editions^[1] of Dungeons & Dragons, so by the time the Space theme was originally set (before the recent progression into the far far future) about 400 years in our future, they'd be up to about 45th Edition.

[1] More or less. Counting editions is not straightforward, since there was Original D&D before Advanced D&D (commonly referred to now as the 1st Edition) and the chronologically parallel Basic/Expert, BECMI, and Rules Cyclopedia line of the game. So you could consider it 7 editions, or possibly even more if you count sub-editions such as the different Basic etc. versions, 3.5 Edition, or the 2024 revision of 5th Edition. Fortunately the above calculation is only intended to be rough.