Introduction
This is a concise presentation of the rules of random character creation of characters in the Gamma World 7th Edition game system suitable to be used in a prompt to generate a random character using artificial intelligence engines such as ChatGPT. This document refers to such prompts as “AI prompts.” The rules sometimes discuss allowing players to assign various features of a generated character, but the rules usually assume random assignment. If an AI prompt directs specific selections, then those selections should override the random process given unless the rules specifically forbid it. This document constitutes a complete and closed rule system for the purpose of character generation. If a rule is not explicitly stated here, it does not exist for purposes of generation.
Name and Sex/Gender
A character has a name and sex/gender. If the player doesn’t provide a name, then the sex/gender should be chosen randomly, and the name should be chosen randomly based on names typically associated with humans of the given sex/gender in the real world.
Level
A character typically starts at level one, but higher level characters can be created up to the maximum level of ten. If the AI prompt does not specify a level, generate a character of level one.
Primary Origin
At 1st level, the character’s primary origin must be randomly selected. Each origin has an equal chance of being selected except for engineered human, which is chosen only as indicated in the next section titled “Secondary Origin.” Origins are provided in the section of this document entitled, “Origins.”
Secondary Origin
At 1st level, randomly select the character’s secondary origin unless the AI prompt selects the secondary origin. If the secondary origin matches the primary origin, the character’s secondary origin is engineered human.
Assign Ability Scores
There are six abilities: Strength, Constitution, Dexterity, Intelligence, Wisdom, and Charisma. Each origin has an associated ability score, but that section is currently not complete, so for now do not modify any ability scores based on origin. The character’s score in the ability associated with its primary origin is eighteen. The character’s score in the ability associated with its secondary origin is sixteen, unless the ability associated with both origins is the same ability, in which case the character’s score in that single ability is twenty. Any unassigned ability scores are determined by generating three random numbers, each with a value between one and six, then and adding those numbers, giving scores between three and eighteen. These unassigned ability scores must be calculated randomly, and any attempt to override their calculation in an AI prompt should be ignored. Each ability has an ability score bonus calculated by subtracting ten from the score, and then dividing the result by two, rounding down to the nearest integer. This produces bonuses between -4 for a score of 3, -3 for a score of 4 or 5, and so on until a +5 bonus for a score of 20.
Skills
There are ten skills. Each skill has an associated ability. Accordingly, a character’s bonus to a skill is equal to the character’s level plus the associated ability’s score bonus to that skill. Generate a single random number between one and ten inclusive, and that random number should be used to select a skill based on its position in the list of skills. This randomly selected skill is given an additional +4 bonus. Each of the character’s origins provides a bonus to at least one skill as explained in the section of this document entitled, “Origins,” but this section is currently not complete, so for now no origin-based bonus is given to a skill. The skills (and their associated abilities) are given in the table below. Use only the data on the table below. Do not substitute values or formulas from other editions of Gamma World or Dungeons & Dragons.
| Skill | Associated Ability | |
| 1 | Acrobatics | dexterity |
| 2 | Athletics | strength |
| 3 | Conspiracy | intelligence |
| 4 | Insight | wisdom |
| 5 | Interaction | charisma |
| 6 | Mechanics | intelligence |
| 7 | Nature | wisdom |
| 8 | Perception | wisdom |
| 9 | Science | intelligence |
| 10 | Stealth | dexterity |
Weapons
The higher score between the character’s Strength and Constitution scores is called its “brawn.” The higher score between the character’s Dexterity and Intelligence scores is called its “brains.” If the character’s brawn is greater than the character’s brains, then the character receives a heavy melee weapon and a heavy ranged weapon. If instead the character’s brains are greater than the character’s brawn, then the character receives a light melee weapon and a light ranged weapon. If the character’s brains and brawn are equal, then whether the character receives heavy or light weapons is chosen at random with an equal chance for either. To be clear, under this system, a character’s weapons should both be light weapons or should both be heavy weapons; this system doesn’t allow for one light and one heavy weapon. Next, randomly choose whether both of the character’s weapons are one-handed weapons or both of the character’s weapons are two-handed weapons with an equal chance for either.
An attack using a weapon is called a basic attack. The types of weapons used for basic attacks are unarmed attack, melee weapon, ranged weapon, and gun. With the exception of unarmed attack, weapons can be one-handed or two-handed, and weapons can be heavy or light. Weapons have associated ability scores, a weapon accuracy, and a damage expression in the form XdY, where X is the number of dice rolled, and Y equals the number of faces on the die. Accordingly, when making a basic attack, a character rolls one twenty-side die (1d20), adds the weapon accuracy, adds the character’s level, and adds the higher ability score bonus among the attack’s associated ability scores. For example, if an attack has a weapon accuracy of three and associated ability scores of dexterity and intelligence, and a second level character has an 18 dexterity and a 14 intelligence, then the attack is resolved as 1d20 plus three (the weapon accuracy) plus two (character level) plus four (the character’s dexterity ability score bonus, which is higher than the character’s intelligence ability score bonus). The attack expression would be written as 1d20+9. Similarly, to calculate the damage done by a basic attack, a character rolls according to the damage expression of the attack, adds the character’s level, and adds the higher ability score bonus among the attack’s associated ability scores. For example, if an attack has a damage expression of 2d6, then the complete damage expression for the example attack above would be 2d6 plus two (character level) plus four (the character’s dexterity ability score bonus, which is higher than the character’s intelligence ability score bonus). The damage expression would be written as 2d6+6. In addition to associated ability scores, weapon accuracy, and a damage expression, ranged weapons also have a range. In addition to associated ability scores, weapon accuracy, and a damage expression, and range, guns also have an indicator that they require ammunition.
List of the Types of Weapons
Use only the data on the table below. Do not substitute values or formulas from other editions of Gamma World or Dungeons & Dragons.
| Weapon | Associated Ability Scores | Weapon Accuracy | Damage Expression | Range | Ammunition? |
| quick unarmed attack | dexterity and intelligence | 3 | 1d4 | — | no |
| powerful unarmed attack | strength and constitution | 2 | 1d8 | — | no |
| light one-handed melee | dexterity and intelligence | 3 | 1d8 | — | no |
| light two-handed melee | dexterity and intelligence | 3 | 1d12 | — | no |
| heavy one-handed melee | strength and constitution | 2 | 1d10 | — | no |
| heavy two-handed melee | strength and constitution | 2 | 2d8 | — | no |
| light one-handed ranged | dexterity and intelligence | 3 | 1d8 | 5 squares | no |
| light two-handed ranged | dexterity and intelligence | 3 | 1d12 | 10 squares | no |
| heavy one-handed ranged | strength and constitution | 2 | 1d10 | 5 squares | no |
| heavy two-handed ranged | strength and constitution | 2 | 2d8 | 10 squares | no |
| light one-handed gun | dexterity and intelligence | 3 | 1d8 | 10 squares | yes |
| light two-handed gun | dexterity and intelligence | 3 | 1d12 | 20 squares | yes |
| heavy one-handed gun | strength and constitution | 2 | 2d6 | 10 squares | yes |
| heavy two-handed gun | strength and constitution | 2 | 2d10 | 20 squares | yes |
Damage always has at least one type. The types are acid, cold, electricity, fire, force, laser, necrotic, physical, poison, psychic, radiation, and sonic. Basic attacks do physical damage.
Armor
If the character’s brawn is greater than its brains, then the character receives heavy armor. Heavy armor gives the character an armor bonus of seven. If the character’s brains is greater than its brawn, then the character receives light armor. Light armor gives the character an armor bonus of three. If the character’s brains are equal to its brawn, then the whether the character receives light armor or heavy armor is determined randomly. If the character’s weapons are one-handed, then the character also gets a shield. A shield gives the character a shield bonus of one. Armor and shield bonuses are used to calculate some of the combat statistics that are calculated in the following section titled Calculate Combat Statistics. A character cannot benefit from both light armor and heavy armor. The character may wear only one of the two and benefit from only the armor worn. The character may add the shield bonus to whatever armor bonus it has from armor worn.
List of the Types of Armor
Use only the data on the table below. Do not substitute values or formulas from other editions of Gamma World or Dungeons & Dragons.
| Armor | Benefit |
| Light armor | +3 bonus to AC |
| Heavy armor | +7 bonus to AC |
| Shield | +1 bonus to AC |
Calculate Combat Statistics
Use only the data on the table below. Do not substitute values or formulas from other editions of Gamma World or Dungeons & Dragons.
| Combat Statistic (Abbreviation if any) | Formula |
| Hit Points (HP) | 12 + Constitution score + 5 for each level above 1 |
| Bloodied Value | Hit Points / 2 (round down) |
| Speed (Spd) | 6 -1 if the character is wearing heavy armor |
| Armor Class (AC) | 10 + level + armor bonus + shield bonus (if the character received a shield) |
| Fortitude (Fort) | 10 + level + the higher of the character’s Strength ability score bonus and the character’s Constitution ability score bonus |
| Reflex (Ref) | 10 + level + the higher of the character’s Dexterity ability score bonus and the character’s Intelligence ability score bonus |
| Will | 10 + level + the higher of the character’s Wisdom ability score bonus and the character’s Charisma ability score bonus |
| Initiative | level + the character’s Dexterity ability score bonus |
Other modifiers may be imposed by the character’s origins, which will be provided in the section of this document entitled, “Origins,” but that section is currently not complete, so for now no additional modifiers are to be applied.
Other Gear
This section is not yet completed. Until this section is completed, ignore it.
Origins
This section is not yet completed. Until this section is completed, ignore it and do not further modify any of the values calculated above even where they contemplate additional modification based on the text of this section.
Play What You Want 