Champions could build almost anything. That was its glory and its barrier. If you wanted cosmic heroes, martial artists, armored inventors, psychic detectives, speedsters, alien monarchs, and street-level vigilantes in the same campaign, HERO System could do the math.

But you had to do the math.

By the early 2000s, the other major superhero RPG lines had faded from the shelf. Marvel Super Heroes was gone. DC Heroes was gone. West End’s DC Universe had not become the new center. The superhero table still existed, but the obvious active heavyweight was Champions, and Champions asked a lot from a new player before the first punch landed.

At the same time, the d20 System was everywhere.

The Open Gaming License had turned D&D’s basic mechanical language into a public construction site. Publishers were making feats, classes, prestige classes, monsters, spells, settings, alternate magic systems, and whole shelves of fantasy material. Most of it still thought like D&D.

Steve Kenson heard something else in it.

He heard a superhero game trying to get out.

THE d20 DEMOLITION JOB

Mutants & Masterminds arrived in 2002 from Green Ronin.

It kept the part of d20 that millions of players understood: roll a twenty-sided die, add a modifier, beat a target number. Then it started taking things away.

Classes went.

Hit points went.

The ordinary experience grind went.

In their place came a point-buy superhero construction kit. Characters were not defined by a fantasy class. They were built from abilities, skills, feats, powers, complications, and trade-offs. The goal was not to ask whether your hero was a fighter, rogue, cleric, or wizard.

The goal was to ask what the hero could do.

That is Kenson’s core move. Powers are not defined first by their comic-book costume. They are defined by effect.

A blast of flame, a beam of cosmic force, a mystic curse, and a lightning strike can all be built from the same underlying damage logic, then flavored differently. Flight might be wings, gravity control, anti-matter propulsion, magic, alien biology, or a jetpack. The rules care first about what happens at the table. The fiction tells us what it looks like.

That sounds simple once someone builds it well.

It was not simple in the d20 boom.

Most d20 publishers were bolting things onto D&D. Kenson stripped D&D down until only the useful chassis remained, then rebuilt the rest for another genre.

The Toughness Save

The most visible change was damage.

D&D combat is attrition. You have hit points. Attacks reduce the pool. When the pool runs out, the character drops. That works for dungeon fights, monsters, and tactical resource pressure.

It feels wrong for superheroes.

In superhero stories, the big question is rarely whether a hero has 73 remaining points of health. A punch either bounces off, staggers them, sends them through a wall, or ends the fight. The drama comes from impact, condition, and reversal.

Kenson’s answer was the Toughness save.

When a hero gets hit, the player rolls against the attack’s damage. Success means the hero shrugs it off. Failure creates conditions. A small failure might leave them bruised. A bigger failure can daze, stagger, or incapacitate them. Bruises make later saves harder, so the fight still has pressure, but the pressure is expressed through condition and momentum rather than a slowly draining bucket.

That is why Mutants & Masterminds fights feel different from D&D fights even though both use the same die.

The twenty-sided die still rolls.

The fiction changes.

A brick takes a tank shell on the chin and keeps moving. A speedster gets clipped once and suddenly the whole room feels dangerous. A cosmic villain shrugs off the first salvo until one clean hit changes the scene.

The math can be swingy. That is the trade-off. A flat d20 roll means luck matters. A bad save can drop someone fast, and some groups never love that. But superhero comics are built on sudden reversals. Kenson made the swing part of the genre instead of pretending superheroes were just adventurers with bigger health pools.

The Power Level Ceiling

The quieter innovation is the Power Level cap.

Point-buy superhero games have an old problem. If players can buy almost anything, they can also break almost anything. One character pours every point into damage. Another becomes impossible to hit. Someone else builds a power combination the GM did not see coming.

Kenson’s Power Level system gives the table a ceiling.

At a given Power Level, attack bonus and damage rank are linked. Defense and Toughness are linked. You can trade within those limits, but you cannot ignore them. A hero might hit often and do moderate damage, or hit less often and do enormous damage. A nimble hero can be hard to touch but fragile when caught. A tank can absorb punishment but be easier to land a blow on.

The cap does not make every hero the same.

It makes difference playable.

That is the elegant part. The martial artist, armored powerhouse, alien demigod, and gadgeteer can all sit at the same table without needing to pretend they are built from the same fantasy class. They are balanced by trade-off, not sameness.

For a superhero game, that matters more than almost anything.

Superhero teams are inherently unfair. Batman and Superman standing beside each other is a design problem. Kenson did not solve it by making every hero equal in fiction. He solved it by giving the game a mathematical conversation about where each hero pays for what they can do.

Freedom City And The Big Shelf

Mutants & Masterminds was not just a rules engine.

It came with a world.

Freedom City began as superhero setting work Kenson had developed before M&M became a published game. Green Ronin turned it into one of the line’s central assets, a full superhero city with legacy heroes, villains, history, organizations, cosmic threats, and enough built-in genre grammar for a group to start playing without building a whole continuity from scratch.

That was important because superhero RPGs need more than powers. They need a shelf of implied history.

Comics are continuity machines. A city needs old heroes, retired heroes, statues, villains who remember last time, alien invasions nobody agrees about, secret labs, newspaper offices, magic corners, and a downtown that has somehow survived seventeen apocalypses.

Freedom City gave M&M that kind of scaffolding.

The line kept growing. Mutants & Masterminds won ENnie recognition. Later editions refined the math and presentation. DC Adventures used the third edition engine for an official DC Comics role-playing game. That was a clean validation of the system: when DC needed an engine for Batman, Superman, Wonder Woman, Green Lantern, Flash, and the rest of the universe, it used the structure Kenson had built.

The superhero problem had a new default answer.

True20, Icons, And The Other Side Of The Brain

Kenson did not stop with Mutants & Masterminds.

True20 Adventure Roleplaying extracted some of M&M’s lessons into a broader system. It simplified character roles, kept the Toughness save idea, and tried to make the engine speak more genres than superheroes.

Then came Icons Superpowered Roleplaying in 2010, and it showed the other side of Kenson’s design brain.

Icons is lighter, faster, and more improvisational. It uses random character generation. It leans into quick play. It gives players Determination, a narrative resource that helps heroes bend the story, trigger qualities, and pull off comic-book turns.

That matters because Kenson could have stayed in one lane.

He did not.

Mutants & Masterminds is the toolkit for people who enjoy building powers carefully. Icons is the pickup-game cousin, the one that wants a hero on the table now. Both are superhero games. Both come from the same designer. They answer different table needs.

That range is part of the Kenson story.

The Professional Translator

Kenson’s career began before Mutants & Masterminds.

He entered the industry through Shadowrun work and became a full-time freelancer in the 1990s, writing across major RPG lines and publishers. He worked inside other people’s systems long before he built one of his own. That background matters because Mutants & Masterminds feels like the work of someone who knows what to keep.

He is a translator more than a pure inventor.

He takes an existing game language and teaches it a new dialect.

With Mutants & Masterminds, he made d20 speak superhero. With True20, he pulled that language outward into broader adventure. With Icons, he moved toward fast comic-book play and narrative currency. With later work on projects like The Expanse RPG and Trinity Continuum: Aberrant, he kept showing the same habit: understand the genre, then tune the machine until it speaks in that genre’s rhythm.

That is not lesser work.

It is hard work.

A bad translation keeps the words and loses the meaning. A good one makes the new language feel like it was always supposed to say this.

What He Actually Built

Steve Kenson did not invent superhero role-playing. He did not create point-buy gaming, condition tracks, hero points, or effects-based design from nothing. Champions, DC Heroes, Marvel Super Heroes, Fudge, HERO System, and other games were already part of the long superhero RPG conversation.

What he built was the cleanest bridge between d20 familiarity and superhero flexibility.

He made superpowers into a toolkit. He made damage feel like impact instead of attrition. He made Power Level trade-offs do balance work without flattening the genre. He gave Green Ronin a superhero line that could last, revise, license, expand, and eventually carry DC Comics.

That is the achievement.

Not the first superhero RPG.

Not the most granular.

Not the only good one.

The one that proved d20 could fly.

Where To Find Him

Kenson remains publicly tied to Mutants & Masterminds, Green Ronin, Icons, and superhero role-playing more broadly. Green Ronin continues to support Mutants & Masterminds, and the line is moving into a new edition era with fourth edition development publicly underway.

His broader credits include The Expanse RPG, Trinity Continuum: Aberrant, D&D work, fiction, essays, and a long trail of supplements across the modern RPG industry. He is also visible as an LGBTQ+ creator and advocate in tabletop spaces, including past work around queer gaming panels and representation.

If you want to understand his place in the hobby, start with Mutants & Masterminds.

Build a hero.

Then notice what the system asks first.

Not what are you called?

What can you do?