OneDice

From publisher blurb:

OneDice is an easy, quick and flexible Roleplaying Game (RPG) system.

Whether you want to design worlds where you play mighty barbarian heroes exploring a fantasy land, rebels on the run in outer space, superheroes fighting supervillians, or anything else, the OneDice system has been developed to be easily adaptable for your games.

A six-sided dice is the only dice you need to play the game. When you want your character to do something that is risky (such as have a fight, climb a steep cliff, etc.), the Gamekeeper will give you a Target Number and ask you to roll a dice to beat it. You’ll roll a number between one and six – which you might get to add a bonus to. What you rolled, including bonuses, is compared to the Target Number. If you equal it or beat it, your character succeeds in what he or she was trying to do, if you don’t, your character fails.

If you fail, you might need to spend some Stunt Points to save your character. Everyone has some Stunt Points at the start of each game session. You can use these to perform cool stunts or avoid disaster.

So it’s simple – you roll your dice, add any bonuses, and find out if yourcharacter has had a success or failure.