Independent, GM-first, free
Who Sinister 6 is for
Sinister 6 is built for the person running the game: the Game Master with a session in a few hours and a table about to do something the notes never predicted.
You have friends showing up soon, a plan the players will ignore, and no appetite for reading a rulebook cover to cover just to keep a scene moving. This site exists for the ten seconds between a player asking a question and you needing an answer.
Everything here is written for real play, not for the shelf. The tools roll in one tap and hand you the part of prep that actually shapes a scene: a villain with a want and a wound, an NPC with a voice you can hear, a fight tuned by action economy instead of a spreadsheet. The guides explain the heuristics behind the rolls so the output holds up once the players start pushing back. No lore dumps and no padding to hit a word count.
It is system-generic on purpose. You get characters, motives, and encounter shape rather than copied numbers, so the result drops into Dungeons & Dragons, Pathfinder, or your own homebrew and uses the math you already trust.
Sinister 6 is not affiliated with, endorsed by, or connected to any game publisher, and it does not reproduce their rulebooks. It is one GM's toolkit, shared because the fastest way to a memorable villain should not cost anything.
Take what fits, change what does not, and get back to the table. If a roll saves a session or a guide gets something wrong, the contact page tells you how to reach a real person.