While not necessarily the most important part of the game, the majority of the Hero System's crunch revolves around characters attempting to help, hinder, heal, and harm one another, and this most often occurs in the overarching structure of combat. This page will attempt to list out all of the important rules of combat in a navigable way, and will also attempt to offer reasons that you might want to take certain non-standard actions.

Unless stated otherwise, characters are all assumed to be acting at SPD 2 while out of combat.

If, outside of combat, a character is attacked by surprise, they take 2x STUN from the attack. Placed shot modifiers against them are also halved.

Combat is broken up into a series of Turns, each containing 12 Segments, which in turn each represent 1 second of time. In a given Turn, each character may act during a number of Segments equal to their SPD characteristic. A Segment in which a character can act is called their Phase. The specific Segments in which a character gets a Phase is also determined by their SPD, as shown below:

Within a given Segment, characters act in the order of their DEX, with the highest going first. If two or more characters have the same DEX and act in the same Segment, each rolls 1D6 to determine which of them acts first. However, if the exact timing of two characters with the same DEX is important, a DEX contest will determine which effect takes place first. If the contest is a tie, both actions happen simultaneously. A character that loses this DEX contest cannot Abort to a defensive Action, but can Abort in lieu of participating in it.

Combat begins on Segment 12. If one or more characters are surprised by the start of a combat, those characters do not act until the following Turn.

When it's time for a character to act, during their Phase, they can perform one or more Actions. Actions are broken down into a handful of basic types, based on how much of a character's time they require.

Full Phase Actions require the character's entire Phase to perform. A character that performs a Full Phase Action can do nothing else on their Phase besides performing Zero Phase Actions prior to their Full Phase Action, or performing Actions which take no time.

Half Phase Actions only require half of a character's Phase to perform, and as such a character may perform two of them in a given Phase.

Zero Phase Actions must be performed during the character's Phase, but otherwise have no limit in terms of how many or how often they can be used, though certain kinds of Zero Phase Actions specify such limitations.

Actions which take no time can be used whenever and however often a character likes, including during other characters' Phases.

Additionally, any kind of Action that requires the user to make an Attack Roll is an Attack Action. A character's Phase immediately ends after they take an Attack Action.

Rather than act when they normally receive their Phase, a character may opt to delay acting, either by specifying a lower DEX value on which to receive their Phase, or by specifying some condition on which they will act.

A character may perform a Half Phase Action and then Hold another Half Phase Action.

A held Action is lost at the start of the next Segment in which the holding character receives a Phase.

If a character is the target of a harmful effect, they may choose to Abort to a defensive action, gaining its benefit before the instigating effect takes place. Aborting costs a character their next Phase.

A character can Abort to multiple defensive Actions at the same time as long as they aren't mutually exclusive.

A character can't Abort in a Segment they've already acted in.

A character that is Holding an Action can Abort the held Action rather than their next Phase.

A character that Aborts cannot Abort until after the Phase they would've had has passed.

As a Full Phase Action, a character can pick one of their movement abilities and move up to the number of meters listed for that mode of movement. Alternatively, as a Half Phase Action, a character can do the same but only move up to half of the mode's movement distance.

Most movement modes also have a 'Noncombat Movement' option, allowing the user to move up to twice their movement distance, or more. Characters using noncombat movement have 0 OCV and 1/2 DCV. Characters can still use noncombat movement as a Half Phase or Full Phase Action.

In almost all cases, when one character wants to affect another character with a power or something similar, they must go through the following steps to resolve the attempt.

First, the attacker must declare what power is being used and the target, then spend the END cost of the power accordingly.

Then, the attacker must make an Attack Roll. To see if the attacker hits, they add 11 to their OCV and subtract a roll of 3D6 from the sum. The resulting number is the DCV the attack can hit. If the DCV that can be hit is greater than or equal to the DCV of the target, the attack successfully hits.

If the 'attack' being used is beneficial, the target may opt to allow themselves to be hit, foregoing the Attack Roll.

Assuming an attack successfully hits, the attacker then determines the effect of the attack. Dependent on what power is being used.

If the attack is one that deals damage, after determining how much damage is being dealt, the attacker rolls 3D6. This determines which part of the body the attack hits. The part of the body applies a multiplier to the damage dealt.

Alternatively, when declaring an attack, the attacker may target a specific part of the body, at the cost of an OCV penalty. If they hit, they automatically hit that location instead of rolling.

N STUN and BODYx are applied after defenses are subtracted. STUNx is applied before.

The hit penalties are halved if the target is Surprised and out of combat.

If the attack is one that deals damage, it can also knock its target down or back. Roll 2D6 and subtract it from the amount of BODY rolled for the attack before defenses were applied. If the result is negative, nothing happens. If it's 0, the target is knocked down. If it's positive, the target is knocked back a number of meters equal to twice the result.

The basic form of attacking with a power is called Strike. There are numerous other ways you can fight, and these variations are called Combat Maneuvers. Combat Maneuvers require 1 END to use in addition to the base cost of the power they're being used with, if any.

Many Combat Maneuvers modify the OCV and DCV of the user.

Core combat maneuvers:

Optional combat maneuvers:

• Choke
• Club Weapon
• Cover
• Dive For Cover
• Hipshot
• Pulling A Punch
• Roll With A Punch
• Snap Shot
• Strafe
• Suppression Fire

Zero Phase Action. 1/2 DCV. +2 OCV only to negate the Range Modifier.

Attack Action. -2 OCV. Roll to hit. On a hit, attacker and defender roll 1D6 per 5 points of STR and count BODY. If the attacker wins, defender's weapon goes flying out of their hand.

Half Phase Action. Counts as an Attack Action. +3 DCV. Can't attack.