Wizards call it the Call of Chaos. Alchemists call it SEMS - Spontaneous Eruptive Mutation Syndrome. Most people call it demon possession or black magic and kill the afflicted. Most cases of hypermorphosis are terminal and cancerous.

But yours was not. You escaped capture by wizards, vivisection by alchemists, and lynching by the rest. Your body was warped and roiling with the energies of change but mercifully cancer-free. Your desire to live has never been stronger, and the changes keep coming. Perhaps, with some experience, you can steer them.

Note: this class assumes the use of a LARGE mutations table, with both good and bad mutations. The Coins and Scrolls blog has several excellent options, but as a rule of thumb you should never be at risk of exhausting the list.

Special: Only humans are mutation-prone enough to take Template D of this class.

Starting Equipment: A quarterstaff, half a dozen belts, a voluminous and concealing cloak.

Starting Skill

Any, roll on a table of failed careers or pick one.

For each template of Hypermorph you have, gain +1 HP and -1 on saves versus mutation.

A: Hypermorphosis, Survivor Strain

B: Nudge, +1 Mutation

C: Adaptive Constitution, +1 Mutation

D: Manifleshed Destiny, True Mutation x2

Hypermorphosis

Roll 6 mutations and choose 3. Normally, you develop aggressive forms of cancer in all mutated body parts, but see Survivor Strain. Your tolerance for mutations is increased (if relevant, you can have twice as many mutations as normal for a character like yourself, and mutations do not generate encumbrance).

Survivor Strain

You are immune to cancer. Mutations cannot reduce your stats below 2 plus your [templates] of Hypermorph. You can resist the onset of a mutation for [templates] minutes, potentially allowing you time to save yourself from an otherwise lethal mutation.

Nudge

Aha! You can slightly - but significantly - influence what mutations you receive. Whenever you receive a new mutation, you can increase or decrease the number rolled on the table by 1. You can also roll any subsequent die rolls (such as for affected limb or number of new eyes) twice and choose your preferred result.

If a rolled mutation allows the Referee or your fellow players to choose a mutation for you, you cannot adjust their choice but you still get to roll twice and choose on any follow-up rolls.

Adaptive Constitution

You are a generally improvised-looking creature. Now it’s time to adapt and overcome. Mutations cannot reduce your speed or hit points, and they cannot take away your primary sense.

Manifleshed Destiny

You are a prince among mutants, the supposed frailty of your human heritage having become your greatest strength. Gain a bonus on reaction rolls versus creatures that have mutations equal to their number of mutations, maximum +4. You can speak with other mutants as if you shared a language. Whenever you gain a level (including this one), gain a random mutation.

True Mutation x2

You develop two powerful and always beneficial mutations that are each approximately as strong as an Inventor Necromancer Invention. These are your “signature mutations”, cannot be overwritten by future mutations, and do not count against any mutation limits.

Design notes:

It’s difficult to create a mutant class. Mutations are absurdly diverse mechanically and anyone can theoretically get them. Because this class does not insist on a particular table of options, there’s really no guarantee of balance. But this design does try make sure that mutations are a reasonable option to pursue, even if they aren’t predictable. Here are some of the design points:

1. No choosing mutations. At least, not from the whole list. Nudge means that the Hypermorph is picking the best of 3 after the second template, which probably means you won’t ever have any truly awful mutations once you hit that template. This will depend on the sorting of the table you use of course. Some mutation tables stack all the negative mutations on one end of the table.
2. No removing mutations. It would feel min-maxxy and fake if the mutant class had a built in way to unmutate. That said if your game has a mutation cap, I would allow you choose which mutation to lose whenever you receive a new mutation while at your maximum. The only way out is through.
3. No self-determined mutation rate. I went back and forth over the idea of giving the Hypermorph a way to mutate himself at higher templates - the Biomancer can mutate himself quite easily. Did it make sense for the wizard to be able to mutate faster than the dedicated mutant? I concluded that the answer was yes. The wizard’s mutations are far more random and dangerous, and the wizard scales off of spells. The Hypermorph scales off of mutation. Sources of additional mutations are valuable loot to a Hypermorph. They are his Notches.

Also, the class is human-only for template D. Scrap it in your games if you like, but I do like the idea that the uniquely mutation-prone species can reach the highest heights of mutation power - turning a weakness into a strength.