Teenage Mutant Ninja Turtles & Other Strangeness

Teenage Mutant Ninja Turtles & Other Strangeness, or TMNT RPG for short, is a tabletop role-playing game based on TMNT universe. It was released in 1985 by Palladium Books, before the famous TV series, and is based on the original comics. It was also one of the first RPGs with Palladium's Megaversal System and so has affected the rules for all upcoming Palladium games, including as Rifts.

Background
Megaversal System is known for the character generation mechanics that starts with the background. Not all backgrounds make for the same power level: "secret agent" mutants begin the game with more skills and equipment than "ferals." The main reason for backgrounds, though, is giving players and the game master ideas for stories. In spirit of this, "strong" and "weak" characters have equal potential for stories, for making and solving different problems.

BIO-E
The core difference between TMNT RPG and preceding Megaverse games is its animal mutant generation system. The character "starts" as a fully zoomorphic animal and without any animal powers. Each species has a number of BIO-E - bioenergy points - that Player can spend for anthropomorphic features and powers.

Hands, legs, speech and "appearance" are anthropomorphized separately in three stages: not anthropomorphic, partially anthropomorphic and fully anthropomorphic. This system allows for fully zoomorphic characters, classic anthro characters and near-humans. It also allows for strange combinations such as human-faced character with non-taur zoomorphic body or bipedal animal, with hands and other features fully zoomorphic. Such combinations are not mentioned in-text and not shown on illustrations, but are noticed in fan-works.

Player can also change size of their character. Size starts at species' level, so no change translates to the character exactly the size of its species. It affects attributes, for example, reduces speed for characters too big or too small and improves strength by size. Increasing size costs BIO-E while reducing size gives additional BIO-E. That's why bigger animals start with less BIO-E, up to 0 points, to balance out what Player will probably get for size reduction; leaving the character huge also has advantages.

Animal powers include natural weapons (claws, bite, talons...) and special animal properties, such as poison and turtle's shell. Each species has a list of powers with corresponding costs in BIO-E. Player can also buy psy powers (independently of species). For characters in other Megaversal games, psy powers require keeping track of Inner Strength Points - resource or "mana" needed for using psy; but mutant animals don't have this game mechanic. For them, psy powers can be used at any time, at will, according only to the power's description.

Legacy
After the Bomb RPG started out as a post-apocalyptic adventure for TMNT RPG. It quickly became a setting on its own, with a line of books dedicated to it. Material from these books is fully compatible with TMNT RPG, as well as TMNT RPG material is fully compatible with After the Bomb games. Later, when Palladium Book's license for TMNT universe has expired, After the Bomb got its own corebook (before that, TMNT RPG corebook and AtB original adventure were required to play After the Bomb).

Animal mutant characters, albeit with a limited set of species, were included in 2nd edition of Heroes Unlimited RPG. Some crucial species missing from After the Bomb (tiger) can be found Heroes Unlimited.

TMNT RPG has advanced Megaversal System's martial arts mechanics. Additional moves and rules originating in TMNT RPG were included in later Megaverse books, so all current Megaversal games allow for robust martial arts combat. First printing of TMNT RPG also included rules for drug addiction, but later it was censored and excluded from following printings. First printing books were sold with white sheets glues on the corresponding pages. It is one of early examples of censorship in RPGs.