Everyone knows that Gamma World demanded the random rolling of mutations through the use of a percentile table, but what about Metamorphosis Alpha. Here's what its rulebook says on the topic:
A player character choosing to be a mutation, whether humanoid or monster-like, has ... physical and mental mutations. These last two abilities are determined by rolling a four-sided die once for physical mutations and once for mental mutations and allowing the player to pick from one to four powers, with the only limiting factor being the number of powers given by the die roll.Now, that passage alone is quite interesting, but it gets better:
The referee must make sure that the monster mutations taken by players when choosing are consistent. Thus, if a player chooses to have wings, then he or she cannot also expect to be taller (and thus heavier). The referee should, as always, use his judgment and discretion in such matters.I should briefly note here that each character has one or more defects as well and these are randomly determined by the referee in secret beforehand, but, otherwise, Metamorphosis Alpha provides no mechanism for randomly rolling mutations. In fact, there are no tables of mutations in the book at all, only a list. It's also worth noting that the descriptions of some mutations include "limitations." For example, a mutant who is "gills" cannot have any sonic abilities, while one who has "wings" cannot be taller or have a total carapace. Of course, the rulebook goes on to explain that. although PC mutants may not have such forbidden combinations of mutations, NPC species may. No explanation for why this should be the case is offered beyond the obvious inference.
As noted already, everyone knows that, in Gamma World, mutations are rolled randomly. But here's what the text of the first edition rulebook actually says:
After determining the relative strengths of all characters’ basic attributes, players electing to play humanoid or mutated animal characters must determine their characters’ mutations. This process can be done in one of two ways. The first way is for the character to roll a single four-sided die twice to determine the number of physical and mental mutations (one roll for each). The number of mutations having been determined, the player then rolls a pair of percentile dice for each mutation, consulting the appropriate chart for results. Using this method, the character may or may not have mutational defects, depending upon the dice roll. The second method of determining a character's mutations is to determine the number of mutations in the same manner as described above, but then to allow the player to pick the mutations he wishes his character to receive. After the player has selected the proper number of mutations, the referee then selects one or more mutational defects in the following manner: a roll of three or four when determining the number of mutations (either physical or mental) indicates one physical or mental mutational defect, as the case may be (or both, if both dice rolls were either three or four). Two rolls of two indicate either one physical or one mental mutational defect (referee’s discretion). Rolls totaling three or less mutations receive no mutational defects. Mutational defects may be found on the same chart as "normal" mutations, and are indicated by the letter “D”.As you can see, even Gamma World retains the possibility of the player's choosing his character's mutations rather than rolling for them by a percentile roll on a table. Granted, that option is listed second in the above paragraph and was not one I think I ever encountered in actual play back in the day, but it's a perfectly legal, by the book option.
The similarities and differences between Metamorphosis Alpha and the first edition of Gamma World got me to thinking about how subsequent editions of Gamma World handled the generation of mutations. The 1983 second edition continues to give each mutant character 1d4 physical and 1d4 mental mutations, determined randomly from a table. However, the rolls on the table are weighted, with the player being able to add his character's Constitution and Intelligence scores respectively to his d100 result for physical and mental mutations respectively. Naturally, defects are at the lower range of results while the best -- such as "Pick Any Good Mutation" -- are at the higher end of the table. Second edition does suggest allowing a player to pick his character's mutations as a safeguard against "hopeless characters," but this suggestion is not presented as a default one, unlike in either Metamorphosis Alpha or first edition.
Gamma World's third edition in 1986 states that all mutants have 1-4 physical and 1-4 mental mutations. Each mutation is rolled randomly on a percentile table, with low scores being less good (and particularly low scores requiring a second roll on the defects table) and high scores being the best (including "Pick Any Mutation"). What's interesting to me is that the third edition specifically states that "In some cases, a character may gain mutations with conflicting results." This possibility is largely (and explicitly) impossible in Metamorphosis Alpha and not discussed in either the first or the second edition of Gamma World.
The 1992 fourth edition gives all mutants 5 mutations to start, the exact ratio of physical to mental determined by rolling 1d6 and comparing it to a table. Players are given the option of having fewer than the rolled number of mutations, if desired. Mutations are themselves generated on a percentile table, where there is no relationship between the number rolled and whether it's a beneficial mutation or a defect (just as in first edition).
The fifth edition in 2000 was a supplement for Alternity. Alternity largely eschewed random rolls for anything pertaining to character creation. However, this version of Gamma World does provide an option for "pure" randomization of physical and mental mutations, as well as defects (here called "drawbacks"). However, the default assumption is that mutations are chosen. Fifth edition introduces the concept of weighted values for each mutation, with some mutations costing more of a character's pool of "mutation points" than others. Defects provide addition points to the pool.
The fifth edition was the last edition to carry a TSR product number (even though it was published by Wizards of the Coast), so it seems a convenient cut-off point for the present discussion. However, I will, in future discussions of Gamma World, talk at greater length about the infamous sixth edition published in 2003 by White Wolf's "Swords & Sorcery" D20 imprint, both for completeness and because I had a small hand in the line and so can offer some insights into it and relationship to what went before. I do not own the seventh edition of the game, published in 2010 and have no intention to purchase it, so I'm afraid I won't have anything to say about it in future posts.