The conclusion of a riveting two-part article comparing Metamorphosis Alpha and Gamma World mutations
In Metamorphosis Alpha (but not apparently in Gamma World) a mutant with more than one mental mutation must have a mental resistance of at least 12.
The differences between Gamma World and Metamorphosis Alpha regarding the 'precognition' mutation are detailed in this post.
Just as in Metamorphosis Alpha, the 'heightened intelligence' mutation in Gamma World adds four points to “mental resistance.” While mental resistance is a Metamorphosis Alpha 'ability,' the closest Gamma World attribute is mental strength. Is mental strength increased in Gamma World or just the defensive element of that attribute?* It is interesting to note that in Metamorphosis Alpha a mutant with four mental mutations is required to take 'heightened intelligence' as one of its mutations.
Gamma World mutants are able to 'teleport' about six times farther than Metamorphosis Alpha mutants (30 kilometers vs 3 miles). Also, Gamma World 'telepathy' has a greater range than its Metamorphosis Alpha counterpart by about one-quarter (10 meters vs 25 feet). The radius of effect for 'death field generation' in Gamma World extends five beyond the radius for the same mutation in Metamorphosis Alpha (20 meters vs. 60 feet). However, a 'telekinetic arm' in Metamorphosis Alpha has more than twice the reach of such an arm in Gamma World (50 yards vs 20 meters). Also, 'illusion generation' in Metamorphosis Alpha has a greater range than in Gamma World, but only by one meter (31 meters vs 30 meters). The Metamorphosis Alpha mutations of 'mental control' and 'repulsion field generation' have an extra half-meter range (15.5 meters vs 15 meters). Every little bit helps, I guess.
'Levitation' in Metamorphosis Alpha allows the mutant to rise vertically for a duration of up to 25 turns. Gamma World instead has 'telekinetic flight' is – as one might expect – more versatile and no limit on duration is indicated.
'Mass mind' in Metamorphosis Alpha is more risky than in Gamma World; there is a cumulative 5% chance of death (“mind burnout”) for all participants per melee turn.
Although the Metamorphosis Alpha listing for the 'cryogenics' mutation indicates it “uses the same limitations as pyrokinesis,” the Gamma World listing (with the name changed to 'cryokinesis') specifies that the freezing damage is applied in the same manner.
'Weather manipulation' is more detailed in Gamma World than in Metamorphosis Alpha. There is no area of effect suggested in Metamorphosis Alpha, but Gamma World specifies a ten kilometer radius. Metamorphosis Alpha has a chart of weather conditions establishing the percentile “Chance of Occurring” and the number of turns before the change takes effect. Chances are increased by 10% if the current meteorological conditions are similar to the desired goal. Gamma World requires an initial period of concentration of six turns and at least an additional twelve turns must pass before the conditions begin to change. In Gamma World, there are three weather aspects that can be altered: cloud cover/precipitation, temperature, and wind. The possible extent of change is based on the prevailing conditions; the chance of success drops (and the concentration time increases) for each 'step' away from the current conditions that the mutant desires. Metamorphosis Alpha states if the percentile chance fails, the mutant is unable to attempt another weather change for a day. In contrast, Gamma World states that the mutation is usable once per day if successful; failure requires a full week of rest before another attempt can be made.
In Metamorphosis Alpha, for 'density control (others)' mutation, the listed “advantage of having it is that you slow other attackers down.” Gamma World states that this mutation has a range of thirty meters and can be “an offensive or defensive power on other beings.”
Unlike Gamma World, the 'absorption' mutation in Metamorphosis Alpha states that, once the mutant has 'absorbed' an amount damage of the applicable type equal to its hit points, the mutant takes double damage from that damage type for 24 hours.
The incapacitation period after using the 'molecular disruption' mutation in Gamma World is one day whereas in Metamorphosis Alpha it is one week. Although only incapacitated for a day in Gamma World, the mutation may only be used once every 1d6 days (determined after each use “with result unknown to player”).
Starting on the second turn, two abilities per turn are taken away from a victim of 'de-evolution' in Metamorphosis Alpha as opposed to only one ability per turn in Gamma World. (In Metamorphosis Alpha both 'attributes' and mutations are called abilities but one supposes that this mutation affects only other mutations.)
The description of the 'dual brain' mutation in Gamma World indicates that “any increase in mental strength due to surviving mental attacks is awarded at one-half the normal rate” (i.e., an increase of one point for every ten successfully resisted mental attacks).** In Metamorphosis Alpha, the 'dual brain' mutation “allows a being to figure out any given artifact faster” while Gamma World specifies that 'dual brain' mutants have “a minus 1 on all die rolls when trying to figure out any ancient artifact.” Metamorphosis Alpha uses a percentile chance for discovering how to use artifacts but Gamma World uses a 'flow chart' system. A mutant with scientific 'genius capability' in Gamma World “may subtract 1 point from each die roll when trying to figure out ancient artifacts” while a 'genius (scientific)' mutant in Metamorphosis Alpha subtracts 10% from artifact rolls.
The description of the 'telekinesis' mutation in Gamma World indicates a range of 15 meters.
The description of the 'intuition' mutation in Metamorphosis Alpha says that the mutant is never surprised; this is absent from the Gamma World description.
Missing from Gamma World are the following Metamorphosis Alpha mutations: mental paralysis, temporal fugue, and charismatic effect. Missing from Metamorphosis Alpha are the following Gamma World mutations: empathy, direction sense, molecular understanding, radar/sonar, sound imitation, thought imitation, and total healing.
Gamma World does not have 'mental transparency' mutation listed in Metamorphosis Alpha, but it does have the much more useful 'light wave manipulation' mutation. A mutant using 'mental transparency' cannot make an attack while “invisible” and intelligent beings succeeding with a mental resistance roll can see such a mutant regardless. A mutant using 'light wave manipulation' is not hindered by these limitations and is capable of stopping laser blasts and creating a patch of darkness.
The Metamorphosis Alpha 'anti-leadership potential' defect is very similar to the Gamma World 'hostility field' defect. In Gamma World, beings with an intelligence of less than 17 have a 20% chance of wanting to attack the mutant “upon first entering the field.” In Metamorphosis Alpha, “humans or humanoids” with an intelligence of less than 17 have a 25% chance per day of wanting to fight the mutant. Are mutated creatures and plants in Metamorphosis Alpha not affected? In lieu of intelligence, which ability is appropriate in Metamorphosis Alpha, leadership potential or mental resistance?
* In Gamma World, the 'mental defenselessness' defect specifies “mental strength” but the 'mental defense shield' mutation refers to “mental resistance.”
** While Metamorphosis Alpha allows an increase of mental resistance for resisting mental attacks, Gamma World allows an increase in mental strength for successfully resisting attacks as well as successfully making attacks (p. 19). Do Gamma World 'dual brain' mutants gain mental strength at the normal rate for successful attacks?
The description for 'tangle vines' in Gamma World indicates the perils posed by a large patch (tripping, entwining, and crushing) that are not stated in Metamorphosis Alpha.
While Metamorphosis Alpha has listings for 'poison thorns' and 'poison throwing thorns,' it does not also have a non-poisonous 'throwing thorns' mutation as Gamma World does.
Metamorphosis Alpha states that 'squeeze vines' cause four dice of damage per turn. In Gamma World, 'squeeze vines/roots' inflict only two dice of damage per turn.
Gamma World establishes that the 'aromatic powers' fragrance “can carry up to 10 kilometers” and that saving throws are to be attempted within 30 meters of the plant. 'Aromatic powers' distances are left unstated in Metamorphosis Alpha.
The description for 'berries' in Metamorphosis Alpha provides examples of effects while Gamma World lists eight colors of 'berries,' each with its own effect. “Regeneration” and “decrease mental powers” are Metamorphosis Alpha example effects not mentioned in the Gamma World list.
'Dissolving juices' in Gamma World cause 5d6 damage to organic matter. The same mutation in Metamorphosis Alpha causes 4d6 damage but “no type of covering is protection.”
'Radiated plant fiber' can emit up to intensity 15 radiation in Metamorphosis Alpha but only up to intensity 12 in Gamma World.
'Color sensitivity and imitation' from Gamma World is somewhat similar to 'radiation sensitivity and imitation' from Metamorphosis Alpha; both mutations allow intelligent plants to activate and operate “color band machinery.” The Gamma World mutation allows the plant to change colors and appearance to imitate any other type of plant. The Metamorphosis Alpha mutation allows the plant to “blend in with the damaging power of any given radiation and not be affected.”
In Metamorphosis Alpha, the description of the 'electrical or heat generation' mutation(s) for plants is merely a reference to the physical mutation listing. Gamma World presents more details regarding how plants use these mutations. Plants with 'heat generation,' but without intelligence or “special” sensory organs, “attack anything which comes in range and stand a 25% chance of missing the target.” (My interpretation is that there is a 75% chance of the plant being able to attempt a “to-hit” die roll.) Plants with 'electrical generation' do 4d6 damage as opposed to the 3d6 inflicted by mutated humans and creatures. However, unlike their animal kingdom kindred, plants cannot use this ability every turn; they recharge 1d6 per turn and are 80% likely to wait until completely recharged before releasing another shock.
The following Gamma World plant mutations do not appear in Metamorphosis Alpha: adaptation, bacterial symbiosis, barbed leaves, boring tendrils, carnivorous jaws, explosive and/or radiated fruit or seeds, razor-edged leaves, saw-edged leaves, seed mobility, spore cloud and/or shooting seeds, thorns/spines, and wings/gas bag. The 'symbiotic attachment' plant mutation in Metamorphosis Alpha is changed to 'parasitic attachment' in Gamma World.
'Stasis in periods of darkness' is listed as a mutational defect for plants in Metamorphosis Alpha. In Gamma World, all plants are assumed to have this limitation unless they have the 'daylight stasis' mutational defect (appearing only in Gamma World). The 'low fertility' mutational defect for plants appears in Gamma World but not Metamorphosis Alpha.