“The smell of sweat and blood enters your nose, as the noise of steel on steel draws closer to you. You can hear shouts, human voices that try to organize each other’s actions. The dust blocking your sight slowly settles. The soldiers have heavily wounded the giant, which has entered a frenzied state, blood and acid dripping from its mouth. The giant’s club, which resembles the trunk of a pine tree, smashes down on one of the warriors, burying him with an uncanny, crunching sound. He didn’t get a chance to scream.”
Most, if not all, Role Playing Games include some form of combat. Combat is an easy way to build excitement in an adventure. When words failed, or weren’t even an option to begin with, when your character enters in a gladiator’s competition, even when two of your characters are just friendly sparring with each other, combat is happening.
Strength is used for most melee attacks.
Constitution is used to determine your overall health, if you’re able to resist poisoned weapons, and it is important for casters that need to concentrate on a spell.
Dexterity is used for most ranged attacks and some melee attacks.
Agility is used to define how many actions a character can take, and it’s important for dodging. Also, unarmed combat can be based on Agility
Intellect is used for spells that can be cast in battles. It’s also used to determine how much a character knows about the abilities an enemy has.
Perception is important for most reactions, and a character with a high perception value is harder to surprise. Also, a character with high perception can perform more actions.
Empathy may not sound like it’s important in combat. However, some perks require Empathy checks to try and control enemy behavior (The “Provoke” perk, for example)
Whenever a combat situation erupts, the GM starts the battle by deciding if one or multiple participants are surprised. These combat participants are not allowed to take their first turn. Then, the GM lets the characters act in a specific turn order. This can be an arbitrary number, the result of an AG roll for every character, or even an AG roll after every round of battle.
However, characters can act not only on their turn. Every action in battle costs Action Points (AP) and, sometimes, additional resources like Fatigue or Mana. Any battle participant can interrupt someone else’s actions. When every participant has finished their turn, the round ends, a new one begins and every participant gets their spent AP back. AP are calculated the following way:
AP = 1 + Combat Level + (Agility/3) + (Perception/3) (round up both) + misc.
As an alternative approach, an experienced GM may decide to not use AP at all. This can make the game more flowing and immersive, but it may prove to be difficult to balance.