When it is your turn in a Combat, you may take an Action. This could be activating a Power, Attacking, dragging your unconscious friend to safety, or anything you'd like. Many Actions that do not normally require a roll will require one in Combat due to the time pressure and higher stakes. You may be able to climb a tree no-problem normally, but can you do it while the police are shooting at you?
Attacking is a popular Combat Action. Pick a target in range and specify how you'd like to hurt them, then roll. The relevant Attribute, Ability, Difficulty, and Damage is determined by your weapon, but GMs may apply a Difficulty modifier at their discretion, depending on the circumstances. Shooting a point-blank target is much easier than firing from a moving vehicle during a rainstorm.
While it is often true that the best defense is a good offense, be warned that committing to an all-out attack leaves you vulnerable to other attackers.
A note on flavor for GMs: Oftentimes Players will specify some details about the manner in which they are attacking ("I take aim and try to shoot him in the chest," or "I slide under the creature's belly and stab upwards"). Most of the time, these can be interpreted as standard all-out attacks without additional modifiers. Certain areas of the body being more or less heavily armored are accounted for by standard Armor rules. If desired, you can grant additional damage or change the difficulty, but try to use standard attacks as often as possible. Once the roll is complete and Damage has been determined, narrate the attack based on the outcome, especially if the Player was not specific in how they wish to attack. This a great opportunity to help Players feel badass.
Certain tasks that are unlikely to fail and don't warrant a full Action (such as drawing a holstered, accessible weapon) can be taken as Quick Actions. These actions do not need to be rolled and merely subtract 2 dice from the rest of that round's Action (to a minimum of 0).
Note for GMs: Use Quick Actions instead of split dice pools whenever possible. Players like it when the action moves forward, and splitting too many dice pools can turn Combat into a horrible slog.
Can you think and act at the same time? Not really, it turns out. Whether or not Mental actions require a roll is largely up to GM's discretion, but generally any concerted thinking ("What do I know about this creature?", "How can I solve this door puzzle before the scarabs eat us?") is treated like a standard Action. Sometimes general awareness or "passive" mental actions (does the player notice the shark swimming up behind them?) can be rolled with their own pools without subtracting from the rest of the Action.
Characters may "hold" their Action by specifying an Action and a Condition under which the Action will occur. For example, they may say "I want to shoot the first person who turns this corner." or "I will slit the hostage's throat if they struggle." or "I will follow Jennifer and stab anyone who tries to attack us."
Characters may make a Reaction, even if they are currently holding an Action.
A held Action lasts until the Character's next Action, but actually following through on a held Action will use up the current round's Action, regardless of when the Action was originally held. For example, Jeff declares "I will pull the lever on the electric chair if the convict starts to turn into a werewolf." The current round ends and the next round begins. The convict (whose initiative puts their turn before Jeff's) then begins to sprout fur and fangs. Jeff can pull the lever, but doing so will forfeit the current round's Action.
Held Actions resolve before the Action that triggered them unless the triggering action is the firing of a firearm. Firearms cannot be reacted to without Powers.
Characters may attempt to multitask some actions during combat. This is done by splitting your dice pool.
In order to split a dice pool, first you'll need to determine which actions you plan on taking or might possibly take, and determine the dice pool for each action. The total number of dice you have available to split between your actions is equal to the smallest of these dice pools. For example, a player with 4 Dexterity, 3 Dodge, and 1 Melee wishes to attack his enemy with a sword, and also attempt to dodge his enemy's punches. His Dex + Dodge is 7, but his Dex + Melee is only 5, so he will have to split the 5 dice pool.
Any action taken from a split dice pool must be allocated at least 2 dice. Therefore, if the total dice available is 3 or lower, the dice pool cannot be split and only one action may be taken, since you have to have at least two groups of two, or four dice total, in order to take two actions.
This cannot be done in order to attack a single target multiple times in one turn. You can, however, split your dice pool to attack two or more enemies one time each.
Splitting Actions can cause combats to drag on too long, and should be uncommon, but it is allowed.
Some actions may be labelled as "committed actions". This means that a character who takes this action cannot split their dice pool in that round. They must commit all available dice to taking that particular action. Much heavy weaponry and some rifles, such as sniper rifles, require a committed action to fire. This leaves the shooter vulnerable to attack, the price that is paid for these weapons' high damage.
Powers that require an Action are always considered Committed and cannot be split.
Reactions allow a Character to take their Action before their turn in reaction to another event. Reactions are almost always defensive moves such as dodging or parrying.
If a Character has already used their Action for the round, they cannot perform a Reaction, so be careful when making all-out attacks. Likewise, doing a Reaction will "use-up" the round's Action, essentially putting one Character on the defensive.
Characters cannot React to Firearms attacks without a Power.
Types of Reactions
The three main Reactions are Dodging, Parrying, and Clashing.
To dodge an attack, roll Dexterity + Athletics. The Outcome of the dodge roll is subtracted from the Outcome of the attack roll, and the new Outcome determines whether or not the attack is successful. This means that ties go to the defender (as the Attacker's Outcome has been reduced to 0 in that case).
As always, the standard Difficulty is 6, but GMs may increase or decrease it depending on the situation. If you are laying on your back, it may be more difficult. If the attack is slow and ponderous, it may be easier.
Characters may also "Evade" with their primary Action on their initiative. Make a Dexterity + Athletics roll, difficulty 7. The Outcome of this evasion roll can be divided up and spread around to any income attacks, subtracting from their Outcomes. For example, if you get an Outcome of 3 on your Evade roll, and two attackers each have Outcomes of 2 on attacks against you, you can subtract 2 from the first attacker, bringing their Outcome to 0, but do not have enough left over to reduce the second attacker's Outcome down to 0. You will evade the first attack but be hit by the second.
Characters may parry an incoming melee attack with their own melee weapon. The parry uses their weapon's standard attack roll and difficulty. The Outcome from the parry roll subtracts from the Outcome on the attack roll, and the new Outcome determines whether or not the attack is successful. This means that ties go to the defender (as the Attacker's Outcome has been reduced to 0 in that case).
Characters may also parry hand-to-hand (Brawl) attacks with a melee weapon or with their own Brawl roll. Parrying Brawl attacks with a melee weapon is usually done at -1 Difficulty. A defender wielding a melee weapon may choose whether they want to parry with their weapon or with their own Brawl roll.
Characters may Parry attacks made on other Characters if they are within range.
Clashing is type of a high-stakes Parry that gives the defender a chance to deal damage back to their attacker. The rolls and matchups are all the same as Parrying, but instead of subtracting Outcomes from one another, both Outcomes are compared, and the Character with the higher Outcome deals full damage to their opponent. In the event of a tie, both characters successfully deal full damage.
If you have already spent your Action for a given Round and have not Exerted yourself, you may Exert your Mind to React to an incoming attack. You lose your next Action.