Joker artefacts are the objects left behind by the Jokers to puzzle their successor races. Not to be confused with Joker Worlds, which belong in a different series of books.
- Joker Towers - The most common type, towers have been found on many worlds.
- Tomorrow Strata
- Centre of the Universe
- Ring Stars
- Internal Planets of Protostar V
- Maze on Minos
- Joker Testament - poem