New to Alternity?
Alternity is TSR's skill-based science-fiction roleplaying game from 1998: one set of rules for any future you can imagine, built around what your hero can do and a single, clever dice roll. Here's what it is, how it plays, and why people are still rolling it a quarter of a century later.
A toolbox for the future
Alternity was designed by Bill Slavicsek and Richard Baker and published by TSR, the company behind Dungeons & Dragons. Where D&D is fantasy, Alternity was built for science fiction — not one universe, but any of them: gritty near-future thrillers, starship adventures, alien first contact, post-apocalyptic wastelands.
It's a skill-based game. A hero is defined by the skills you choose and improve, not by a class or a fixed list of powers, and nearly everything they try is a roll against one of those skills.
The core books (the Player's Handbook and Gamemaster Guide) give you the rules; the campaign settings give you somewhere to use them. The line ran until 2000, when Wizards of the Coast, by then TSR's owner, turned its attention to the new d20 System.
The settings
One roll does it all
Everything in Alternity — picking a lock, piloting a starship, a firefight — uses the same roll.
Your hero
Alternity is skill-based: what your hero can do comes from the skills you buy. Start with six abilities — Strength, Dexterity, Constitution, Intelligence, Will and Personality — and a profession: Combat Spec, Diplomat, Free Agent, Tech Op or the psionic Mindwalker, which makes some skills cheaper but none off-limits. Heroes can be human, a mutant or an alien. Skills come as broad skills with specialties under them, and buying ranks in a specialty raises your skill score.
The roll
Roll a d20, the control die, together with a second die, the situation die. Add them (or subtract, if the situation die is a bonus) and try to roll at or under your skill score. Low is good.
How well you did
The lower you roll, the better the result: Ordinary, Good or Amazing success — or Failure, or a Critical Failure when it all goes wrong. A better result means more damage, faster work, a better deal.
The situation die: one scale for every modifier
Instead of adding up +2s and −3s, every circumstance moves the situation die up or down a step. A good tool, a clear shot or a distracted guard steps it toward a bonus; darkness, a moving target or a hard task steps it toward a penalty.
Degrees of success, in one picture
Say your hero's skill score is 13. Roll 13 or less and you succeed. Roll half your score (6) or less and it's a Good success; a quarter (3) or less is Amazing. Every skill works this way, so you always know your odds at a glance.
Combat
Each round has four phases: Amazing, Good, Ordinary and Marginal. Everyone makes an action check — the same roll as always — and the better the result, the earlier in the round they act. Tough, determined heroes get more actions per round.
Damage lands on separate tracks: Stun (knocked out, not hurt), Wound, Mortal (life-threatening) and Fatigue. Attacks are low impact, high impact or energy, and armor protects against each kind differently — a vest that stops a bullet may do little against a laser.
Progress Levels
Technology is rated from PL 0 to PL 9, so the same rules handle a stone knife and a matter transmitter. A setting just picks its level.
Why it stands out
It never really went away
Alternity was only in print for a few years, but the people who played it didn't stop. The skill-based rules are quick to learn and flexible enough to run nearly any science fiction, and the settings are rich enough for years of play.
Fans kept it going with free e-zines, netbooks, house rules and ship designs — many of them in this archive. Much of its design lived on in Wizards of the Coast's d20 Modern, where Dark•Matter and Star*Drive reappeared, and in 2018 Sasquatch Game Studio, with original designer Richard Baker, published a brand-new Alternity edition.
Today there are active groups on Discord, Facebook and Reddit, and tools like AlternityBeyond for building and running heroes online.
“…the combination of variability and shades of performance” — from just two dice.
Stargazer's World review of AlternityYour first session
All free, all here.
Read a Fast-Play
- Incident at Exile -- Alternity Fast-Play GameThe Fast-Play game: quick rules
- The Future's Edge -- Alternity Fast-PlayA shorter free introduction with a starter adventure.
- Dark•Matter Fast-Play RulesThe same idea for the Dark•Matter setting.
- Alternity Hero Sheets (print)The official hero sheets
Watch first
- Inside ALTERNITY: TSR's Forgotten Masterpiece Finally ExplainedA ten-minute overview of how the game plays.
- Your First Alternity Character in One VideoA complete walk-through of building a hero.
Build a hero
Grab a hero sheet above, or build one online with AlternityBeyond, which works out the numbers for you. Then try a few rolls on our dice roller.
Find a group
Ask questions, find players and share your games with the Alternity community. When you want the full rules, the original books and the 2018 edition are on DriveThruRPG.