Xero Sum Engine SRD | XeroSumGames

COMBAT

COMBAT ROUNDS

Combat is divided into rounds which last between 6-10 seconds. Each round is divided into three phases - Initiative, Actions, Resolution.

INITIATIVE
Initiative determines the order in which combatants act. Each participant makes an Initiative Check, adding their Initiative Modifier (from their Secondary Stats) to the 2d6 roll.

The character with the highest initiative score goes first and then it proceeds in order to the lowest score.

In the event of a draw, PCs always beat NPCs. PCs with the same initiative score act simultaneously.
Characters may choose to defer their turn until later in the combat round.

In the second and each subsequent round of combat, any participant that neither attacked nor was attacked receives a +1 modifier on their next Initiative check.

ACTIONS

Each participant gets 2 combat actions per round. They may choose to take the same action twice or take two separate actions.

TABLE 9: COMBAT ACTIONS

RESOLUTION
The resolution phase of the Combat Round takes into account delayed effects from actions and weapons, such as Repositioning or hand-grenades.

Once each character has taken both of their actions and any delayed effects are resolved, the round is over, and the next round begins with an Initiative check.

Remember, in the second and each subsequent round of combat, any participant that neither attacked nor was attacked during that round receives a +1 modifier on their next Initiative check.

GETTING THE DROP
Before combat starts, one character (including NPCs) can Get the Drop, preempting the Initiative check and taking a single combat action before anyone else rolls for initiative.

Only one character can Get The Drop, and if multiple characters attempt it, the one with the highest Dexterity and Acumen Amods wins.

If there is a tie and no clear winner, no one Gets The Drop and combat moves directly to the Initiative phase.

Any character who Gets The Drop automatically incurs a -3 CMod on their next Initiative Roll.

RANGE
Rather than have absolute distances that require measurement, each character’s position to another is relative.

The Range bands are Engaged, Close, Medium, Long and Distant and each band has a value that ranges from 1-5, as laid out on Table 11 Range Bands and described below.

To move between bands takes the same number of combat rounds as the sum of the bands being covered. This means it takes:

1 round to move from Engaged to Close
3 rounds to move from Engaged to Medium
6 rounds to move from Engaged to Long
10 rounds to move from Engaged to Distant

TABLE 2: ATTRIBUTE MODIFIERS

ENGAGED
Close enough to wrestle, Engaged combat gives a +1 CMod to Melee attacks and a -1 to Ranged attacks.

CLOSE
If you can still taunt and threaten your opponent, then combat is at Close range. Melee combat can only take place with a weapon that has an Extended Melee Attack (such as a Spear) and suffers a -1 CMod penalty. Close Range is ideal for Pistols, although any type of Ranged Weapon gets a +1 Range CMod to an attack.

MEDIUM
Far enough away that a pistol shot would be wasted without taking aim but close enough to throw a grenade, Medium range gives no Modifiers to any attack and is perfect for carbines or a bow.

LONG
Too far for an accurate pistol shot but perfect for Rifles, being at long range gives a -5 to any pistol shot but a +1 to a Rifle shot.

DISTANCE
Far enough away that characters will not be able to hear each other without radio equipment and may not even be able to see one another clearly. Only someone with a Hunting Rifle equipped with a score or a Sniper’s Rifle can strike from this range.

DAMAGE

WEAPON DAMAGE

Attacks deal two types of damage that affect the Wound Point and Resilience Point totals of the target.
That amount of damage inflicted is weapon specific and has both a consistent and a random value, such as 5+1d6.

When using Melee Weapons or Unarmed Combat, the Physicality AMod of the user is added to the damage done and written in the format 4+1d6 + Physicality AMod.

For most ranged and slashing weapons, Resilience Point damage is 50% of the Wound Point damage, rounded down.

Attacks inflicting blunt force trauma (such as fists or clubs or batons) may do the same amount of Resilience Point Damage as Wound Point damage. These weapons are marked with 100% RP.
For any character fighting with just their fists, the damage done is 1d3 + Physicality AMod + Unarmed Combat SMod.

SUBSISTENCE DAMAGE

A character can go without food and water for one day without harm, but after that, they will lose 1 Wound and Resilience Point per day from Subsistence Damage.

If they drop to 0 Resilience Points, they become too weak to move and become Incapacitated. At 0 WP, they must be fed to be Stabilized, otherwise they will Die, and any character that becomes Incapacitated through Subsistence Damage will need to be tended to and fed by another character until they heal enough to look after themselves.

A character with a regular food and water supply will heal at a rate of 1 WP and 1 RP per day.

FALLING DAMAGE

Characters suffer 3 points of Wound Point and Resilience Point damage for each 10’ that they fall.

DROWNING

Characters can hold their breath in water for 6 + Physicality Modifier rounds. For each subsequent round, they must make a successful Physicality check or suffer 3 points of Wound Point and Resilience Point damage each round.

If they are reduced to 0 Resilience or Wound Points, they will Die unless another character saves them.

INCAPACITATION

If a character is reduced to 0 Resilience Points, they become incapacitated for 4 rounds minus their Physicality AMod, with a minimum of 1 round.

The character regains consciousness with 1 Resilience Point and recovers 1 additional Resilience Point per round if they are not in combat.

MORTAL WOUNDS

If a character is reduced to 0 Wound Points, they are Mortally Wounded and must be Stabilized, or they will Die within 4 + Physicality AMod rounds.

STABILIZING

If a character becomes Mortally Wounded, they must be Stabilized with a Successful Reason or Medicine check, or by getting a Wild Success with a General Knowledge check.

Once stabilized, the character remains Incapacitated for 1d6 rounds – Physicality AMod, with a minimum of 1 round.

HEALING

Injured characters who weren't Mortally Wounded heal at the rate of 1 Wound Point per day if they are resting.

If the character was Mortally Wounded, they heal at the rate of 1 Wound Point for each two days they are resting.

Resilience Points are recovered at the rate of 1 per hour if the character is resting.

LASTING WOUNDS

A character who is Mortally Wounded must make a successful Physicality check to avoid taking Lasting Damage. If they fail the check, they must roll 2d6 and suffer the corresponding injury listed on Table 11: Lasting Wounds.

These wounds are permanent and cannot be healed.

TABLE 11: LASTING WOUNDS

PANIC

If a character is reduced to 50% of their Resilience Point total (rounded down) then they must make a successful Reason, Psychology* or Inspiration check to flying into a Panic.

If they fail, they roll 2d6 and check against table 11 to see what form their panic takes.

TABLE 12: PANIC

BREAKING POINT

Each character starts with 5 Breaking Point stress boxes. When faced with stress or trauma, they should make a dice check using Reason & Acumen AMods to see if they can work through it. If they fail the check, they fill in one of the stress boxes.

If all 5 stress boxes get filled in, the character has hit their Breaking Point. The player should roll 2d6 and consult Table 13: Breaking Point to see how they react.

Once they have reached their Breaking Point and reacted to it, all the stress boxes are cleared.

Characters can spend time alone or doing things they enjoy in order to clear one of the stress boxes.

TABLE 13: BREAKING POINT