D&D 5E Bringing 2e Gamma World PCs into 5e D&D

[the Jester]

So in the near (?) future, I'm going to be running a crossover game where a 5e party enters the 2e Gamma World setting, has an adventure, then eventually returns to my 5e setting with some GW pcs in tow.

I want to work out a way to convert those GW pcs to a level, which they don't really have in GW, mainly to account for their HD. A few pertinent facts about 2e GW pcs:

• A GW pc's Con ranges from 3 to 18. It's generated by best 3 of 4d6.
• A GW pc's HIT POINTS are a number of d6s or d8s equal to the pc's Con score. There is no "Con bonus" that gets added.
• A GW pc is WILDLY UNBALANCED compared to other GW pcs. The range of power and effectiveness of a Gamma World character is very wide, and is largely randomly determined. I will partially compensate for this by giving 'worse' pcs better starting equipment, gear being the main source of character improvement in GW.

So far what I am thinking is I will create a "Gamma World character" class that GW pcs have to advance through first before they can take "normal" classes, in order to account for their innate "Hit Dice". This class will do the heavy lifting of making them 5e compliant- it will give them their proficiencies, account for their higher than normal for first level hps, etc- and will include a variety of features that will (hopefully) make them a better match for 5e D&D pcs.

I'm going to use this thread to sort of hash out my ideas for doing this. Feedback and ideas are welcome.

 

[Paul Farquhar]

I would keep ability scores, but completely redo hp in accordance with 5e rules. The "value" of 1 hp is not comparable between the two systems. By 5e standards GW 2e weapons do silly (big) amounts of damage.

For Pure Strain Humans and other characters without powerful mutant abilities, they can just pick a class. For other characters I would swap out class or subclass abilities for mutations. You can handle each GW PC on a case by case basis.

 

[LuisCarlos17f]

GW could become a new M:tG in the future, with a lot of retro/vintage sci-fi punk touch. Planar travel was one of the possible mutations.

I imagine mutations working like psionic powers.

GW is a good example of how sci-fi gets old poorly because youngest generations miss current real technology, for example the tablets, the mobiles, new materials or the 3D printer machines to create pieces for broken motors. Some players could wish tech from other sci-fi franchises, for example the transhumanist digital inmortality+mind upload of Altered Carbone(also published as RPG) or Eclipse Phase RPG.

Humanoid

Other point is the technology. Firearms need ammo, motors need energy. Could magic be used to reload (and repair) machines? Maybe a motor only needs ordinary (olive) oil.

You could add characters from other franchises, for example a reimagined version of Robotix, Visionaries, a diesel-punk version of M.A.S.K. or a mash-up of Cobra (G.I.Joe's archienemies).

 

[the Jester]

I would keep ability scores, but completely redo hp in accordance with 5e rules. The "value" of 1 hp is not comparable between the two systems. By 5e standards GW 2e weapons do silly (big) amounts of damage.

The GW pcs will be joining fairly high level D&D pcs. I'm planning to import them as is, then let future levels smooth out the differences. So, for instance, for hit points, they'll keep their existing totals, but new levels will include standard 5e "HD + Con bonus" additions.

But since the GW HD don't have a Con bonus attached, I am thinking that each 'level' of the Gamma World Hero class will have two HD, meaning an 18 Con Gamma World Hero should be roughly equal to a 9th level 5e pc. (I recognize that mutations make this a very tricky prospect.)

For other characters I would swap out class or subclass abilities for mutations.

I was thinking that one subclass might enhance mutations, but I'm still threshing out the details.

Ideally, I want my GW Hero class to basically end up with any GW pc at the equivalent of 9th level, having 18 Gamma World style HD (which feels like it roughly equals 9 5e HD with a Con bonus) and a collection of features that bring them in compliance with the 5e rules: proficient saves, skills, and so on. Obviously, I am still in the early stages

 

[the Jester]

This is my tentative working draft. I would be delighted in some feedback, especially from people familiar with both systems.

EDIT: The radiation resistance ties into a homebrew rule set; probably best to ignore it for now.

GAMMA WORLD HERO

Level --- Prof --- Min HD --- Features
1 --- +2 --- 5 --- Armor/weapon proficiencies, language, save proficiencies
2 --- +2 --- 7 --- Radiation resistance, skill proficiencies
3 --- +2 --- 9 --- ASI/Feat, language
4 --- +2 --- 11 --- Additional skill, expertise
5 --- +3 --- 13 --- Extra attack, gamma boost, language
6 --- +3 --- 15 --- Additional tool, ASI/Feat
7 --- +3 --- 17 --- Additional skill, gamma boost, language
8 --- +3 --- 18 --- ASI/Feat, expertise, superhuman potential

HD Gain: If you have no more than the indicated number of HD, you increase your Hit Dice until you have the minimum for your level. These HD follow Gamma World rules (either d6 or d8, no Con bonus).
Armor/Weapon Proficiencies: You have proficiency in simple and martial weapons, as well as light and medium armor and shields. You also have proficiency in technological weapons and armor of up to your native culture's tech level.
Language: You learn a language of your choice that you have been exposed to.
Save Proficiencies: Choose one of the following ability scores and gain proficiency in saves using that ability: Dex, Con, or Wis. Then do the same with one of the following ability scores: Str, Int, or Cha.
Radiation Resistance: Your constant exposure to radiation in your native plane has left you better able to withstand the ravages of radiation. You gain the following benefits.

• Whenever you gain RADs, you gain 2 fewer than you otherwise would.
• You must accumulate 10 RADs in one round or 20 RADs in a 10 minute period to suffer from mild radiation sickness, and you must accumulate 25 RADs in one round or 50 RADs in a ten minute period to suffer from severe radiation sickness.
• If you are a pure strain human, your radiation threshold doubles, and you never gain mutations.
• If you are a humanoid, a mutant animal, or a mutant plant, instead of the normal long term effects of radiation, you are affected as follows:
  • Threshold +20: Gain 1 level of exhaustion
  • Threshold +30: Gain 1 level of exhaustion, gain one mutation from Gamma World
  • Threshold +40: Gain 2 levels of exhaustion, gain one mutation from Gamma World
  • Threshold +50: Gain one mutation from Gamma World
  • Threshold +70 (and per +20 thereafter): Gain one mutation from Gamma World
  • Threshold x 8: Death.

Skill Proficiencies: At second level,you gain proficiency in three skills of your choice.
ASI/Feat: At third level, and again at 6th and 8th, you take a feat, increase an ability score by 2, or increase two ability scores by 1.
Additional Skill: At fourth level, and again at 7th,you gain an additional skill proficiency.
Expertise: At fourth level, choose one skill or tool you are proficient in. You gain Expertise in that skill or tool. At 8th level, you choose another skill or tool and gain expertise in it.
Extra Attack: Beginning at 5th level, when you take the Attack action, you may make two attacks.
Gamma Boost: At 5thlevel, your post-apocalyptic physiology demonstrates your ability to evolve and adapt. You gain one of the following benefits. At 7th level, you gain another gamma boost. You can take the same boost twice (and Pure Strain Humans must).

• If you are a Pure Strain Human, increase each of your ability scores by 1, and your maximums for each score by 2. In addition, whenever you make an Int check, you add 1d4 to the check. If you take this option twice, this increases to 1d6.
• If you are a Humanoid, Mutant Animal, or Mutant Plant, choose one of the following options.
  • Choose a mutation you have that deals damage measured in dice. When you use that mutation, you can increase the damage by a number of dice equal to your proficiency bonus. These are d10s if the mutation affects one target or d6s if it affects more than one target. Once you use this ability, you must complete a long rest before you can do so again. If you take this feature twice, you must take it for a different mutation each time.
  • Choose one of your mutations that has a duration. Double the duration of that mutation. If you take this feature twice, you must take it for a different mutation each time.
  • Choose one of your mutations that has a use limit. Double the number of available uses. If you take this feature twice, you must take it for a different mutation each time.
  • Choose one of your mutations that requires an action to activate. You can use it as a bonus action once. You must complete a short or long rest before you can do so again, but you don't gain extra uses of the mutation because of this feature. If you take this feature twice, you may take it for a different mutation each time, or you may take it to gain a second use of the same mutation as a bonus action.
  • Your natural armor increases by 3. You can figure your AC using the following formula: 10 + natural armor + Dex bonus.
  • You increase two ability scores by 2.

AdditionalTool: At sixth level, you gainan additional tool proficiency.
SuperhumanPotential: At eighth level,your maximum in all Ability Scores increases by 2.

 

[the Jester]

For clarity, my intention is that the GW pc MUST take the Gamma World Hero class until they attain a level where the class would give them the number of HD they have. In other words, if our hero's Con is 12, and they therefore have 12 HD by Gamma World rules, they MUST take five levels of GWH before branching out into other classes, and MAY go all the way to level 8 if they choose.