RenleyRenfield
Adventurer
In your opinion, what TTRPG is perfectly well mde and totally complete in one volume? That is to say, not only is the game good, but you don't need anything else to play it even long term.
NOTE: it is not required that the game does not have supplements, just that you feel that it does not need any.
I am tempted to say Champions 4E (the Big Blue Book) but the fact is it needs more example villains to be truly complete (so IMOP Classic Enemies completes Champions 4E, even though there are ots of other books I love).
I think my real answer is All Flesh Must Be Eaten. There are supplements for it, but they aren't necessary at all. That game is a real toolkit for all kinds of games, not just zombie survival.
What do you think? What game(s) do you think is totally perfect and complete in one volume?
Marvel Heroic Roleplaying (cortex)
Only the one main book is needed, anything else is superfluous.
Blades in the Dark
Perfect as its. Even the creator's Deep Cuts isn't needed.
Pasion de Las Pasiones
Possibly the most fun/hilarious rpg ever made
Dread
There is no need for anything else for this game to be glorious serial killer fun.