The Metamorphica is system-neutral net-book by Johnstone Metzger, noting a wide range of powers and mutations for a wide range of gaming genre. It it useful for post-apocalyptic, superhero, fantasy, supernatural/horror or space-opera settings, where characters would play or encounter mutants, superhumans, demons, freakish lab-experiments, monstrous aberrations, cosmic horrors or alien creatures.
The Metamorphica comes in two versions: The original version that is free to download, and the Revised version that expands the list of mutations and adds more appendices with a lot more useful tables and procedures for making unusual characters and items. (see below)
The master mutation table lists 650 mutations, in 6 categories (Body: Form, Body: Function, Mind: Behaviours, Mind: Cognition, Psychic Powers, and Supernatural Attributes), and all-together, uses a d1000 (roll with three d10s). If there is a need, each category can be rolled individually or in groups. For example:
- For behavioural mutations, roll 1d100+400.
- For cognitive mutations, roll 1d100+500.
- For mental mutations, roll 1d300+400.
- For mental mutations not including psychic powers, roll 1d200+400.
- For mutations affecting physical functions, roll 1d200+200.
- For mutations affecting the physical form, roll 1d200.
- For physical mutations, roll 1d400.
- For psychic powers, roll 1d100+600.
- For supernatural attributes, roll 1d300+700.
Note, a d300 can be rolled with a d30-times ten, with a d10 for units, while a d200 is a d20-times ten, with a d10 for units. Lacking a d30 or d40, one roll a d10 with a d3 or d4 adjuster. That is, when rolling a mental mutation, you would roll two d10s, a d6 rolled as a d3 (1-2 = 1, 3-4 = 2, 5-6 = 3), and add 400 the the final result. Naturally, you roll one of the d10s as units (0-9), and the second d10 as tens (00-90), but the d3 adjuster might add the ten-die (1 = +00, 2 = +10, 3 = +20). As a simple alternative to a d40 roll, you can make an odds-or-evens roll with any die, with a d20. If you roll an odd numbers on the adjuster, the d20 roll is not adjusted, but if you roll even, you add 10 the the result. (All these roll adjustments are not covered in the book, but are noted to make things easier on players)
Being system-neutral, it is up to the Game Master (Mutant Lord or equivalent) to figure-out how each of the mutations effect the rules. Many of the mutations presented are simple or superficial enough that they may not even effect the game mechanics of the character, instead effecting only the character's appearance, personality lifestyle, and/or NPC reaction.
On top of what is noted on the master mutation list, there are additional tables to help flush-out a character or creatures, even covering different genres (Experiments in Secret, Mutant Superheroes, Post-Apocalyptic Mutants and Swords of the Chaos Lords) and creature types (Beastlings, Demons, Mutant Hordes, Mutant Plants, Uplifted Animals and Xenobiology).
The Revised version adds additional entries to the master mutations list, greatly expands to the appendices, and adds additional artwork. While the the master mutations list is largely the same sets of mutations and powers as the original edition, some revisions were made for errors, renaming and re-grouping.
The first appendix, called Additional Tables, expand to the old tables and now features tables for drastic appearance change (from mutagen, wild magic or whatever), a set of mental and physical mutation tables that breakdown the standard mutations into "favorable" and "detrimental" effects; table for random materials (wood, metal, plastic, etc.), and tables for making abhorrent monsters.
The old Characters by Campaign/Type appendices have been changed onto the following:
After the Fall is highly useful for games like Mutant Future, Gamma World, etc. It adds new procedures for post-apocalyptic mutants (now featuring Human Psychics and Superbeings), procedures for making mutant monsters, reasons for a post-apocalyptic mutant (genetic engineering, gamma rays, etc.), plant societies, and a big d1000 list of random junk (mundane modern items that may or may not be useful).
The Ficto-Techica is all about creating artifacts of magic and/or super-science.
Popular Science has everything you need to run a pulp sci-fi or comic superhero setting. There are procedures for making space aliens, living mad-science experiments, uplifted animals, and a range of comic book superhero types, including their unusual origins.
Swords of the Chaos Lords is for dark fantasy, occult magic and demonic forces. There are procedures for making demons, great and minor; the warriors, sorcerers and cultists of demon-gods, along with their "blessings" in the form of demonic attributes, demon-bound artifacts, steeds, familiars and so on. There are motivations of demonic entities, a big d1000 list of infernal characteristics that happens around a demon, and a summoning mishap table.