A Hero in ACE! has a Role; four Stats—Smarts, Moves, Style, and Brawn—rated between one and five, stats for Defence and Health, and Trait. A Role can be a Talking Animal, another species like an Alien or Goblin or Vampire, a figure out of fantasy such as a Ninja or a Knight, an occupation such an Actor or an Inventor, or a Superhero. A Role provides a special ability, for example, a Kangaroo packs a mighty punch, so inflicts an extra point of damage, whilst a Trait, is a descriptive adjective which primarily serves as a complication, but under the right circumstances, might even be helpful. For example, cynical, Punk Rock, or Vain. To create a Hero, a player divides twelve points between the four stats, adds a Focus—an area of specialisation or expertise—for each Stat, which gives a bonus when using the Focus, and then selects a Role and a Trait. The process is quick and easy.
Trait/Role: Clumsy Dinosaur Detective
Health: 8 Defence: 9
Smarts 2 (Perception 4)
Moves 3 (Juggling 5)
Style 2 (Persuasion 4)
Brawn 6 (Brawling 6)
Mechanically, ACE! uses handfuls of six-sided dice. One die is a different colour, the Calamity Die. To have his Hero undertake an action, a player rolls a number of dice equal to the appropriate Stat or Focus. An Easy Target Number is equal to ten or more, Hard twenty or more, Herculean or more, and so on. These rolls are open-ended as rolls of six explode. If a one is rolled on the Calamity Die and the roll is failure, something goes disastrously wrong for the Hero. The nature of the disaster is determined and narrated by the players of the other Heroes, always for comedic effect. Fortunately, every Hero also has a number of Karma points. These can be spent to add an extra die to a roll, reduce the damage suffered by an attack, negate the effect of the Calamity Die, or to instigate a Flashback to reveal a previous event or action which helps the current one.
Combat in ACE! uses the same rules. Initiative is determined by the Moves Stat and mêlée by Brawn, ranged attacks by Moves, unless the Hero has the Brawling Focus or Shooting Focus, respectively. In either case of the latter, the result of the roll has to be equal to or higher than the defendant’s Defence value. Damage ranges in value from one for a punch, two for a club, and three for a pistol to four for a machine gun, and five for a bazooka. Heroes in ACE! do not die, but they can be knocked out.
ACE! also adds rules for magic with the addition of the Power stat. In fact, the Power stat can be magic, psionics, the power of prayer, and so on. It just depends on the type of game being run, but the Power stat can be used to do anything in the game—it just costs a point of Karma per use. There is no list of spells or psionic abilities, but a player can easily come up with ones of his own.