Although most people avoid combat because they could get killed, violence is often the most obvious solution. Most Interface scenarios have at least threats of combat.

Combat Round

The basic time measure for combat is the combat round. This is a short elastic unit of time -- the time required to do one action in combat. One action in combat includes: Combat rounds continue in succession until everyone is done fighting, either through incapacitation, death, surrender, or flight.


Interface uses the following combat system to determine the winners and losers of a fight:

1. Determination Phase: all combatants state what they are doing this round, including the weapon they will use. Targets and opponents are named. The gamemaster decides whether the players or their gamemaster-run opponents first make their statements of intent.

Characters can fight, or do something else, as listed above. Generally, characters can fight or move, not both.

Characters within a metre of each other need not move to fight.

In cases where it’s important which combat action happens first, they’re resolved in order of speed. This will normally happen only when there are unopposed rolls. A character’s speed is the average of her DEX and her skill with the weapon she’s using.

to speed
weapon type
0 missile weapon
-1 long mêlée weapon (spear)
-2 medium mêlée weapon (katana)
-3 short mêlée weapon (knife), unarmed combat
Example: Lotus Flower is in an argument with a street samurai, who suddenly pulls out a Colt revolver. She wants to knock it out of his hand before he can shoot her. Her DEX is 13 and her Athletics/Fist is 15, so her speed is 14, adjusted by -3 to 11. The street samurai has a speed of 10 with his pistol. Lotus Flower can roll her unopposed attack. She manages to hit him in his arm, causing enough damage that he drops the revolver.

The next round, the street samurai will attack her with his alloy-reinforced knuckles. Since both are choosing melee combat, there will be one opposed roll -- speed doesn’t matter.

2. Resolution Phase: anyone shooting a missile weapon makes an unopposed roll.

Melee combatants roll their respective weapon resolutions, using the opposed resolution system. The results leave a winner and a loser, or two losers. In addition, both critical and fumble rolls have special meaning.

If both fighters roll exactly the same number, and both are successful, then both are losers.

If both fighters fail to make their success rolls, then both missed that round and both are losers. They can try again next round, or try something else.

A critical success can still lose if the opponent receives a roll higher than the roll yielding the critical. The winner still does his normal damage.

If a combatant rolls a fumble, he must make a POW roll. If successful, he merely dropped his weapon. If the POW roll fails, the weapon broke. If he was fighting without a weapon, he instead makes a DEX roll to see whether he slipped and fell. 3. Winner’s Phase: the winner rolls his damage done. He also receives a check for experience in the weapon used, unless he already has such a check.

He must also roll a d20 to determine which location he hit.

mêlée ranged location struck
1-4 1-3 right leg
5-8 4-6 left leg
9-11 7-10 abdomen
12 11-15 chest
13-116-17 right arm
16-18 18-19 left arm
19-20 20 head
If the winner rolled a critical success, he can choose to either roll twice the normal damage, or roll damage normally but declare which hit location was hit. 4. Loser’s Phase: if the loser received a successful skill roll, and if he was using a weapon to parry, then he adds 3 points of protection to his armor that round. If he was using a shield to parry, he receives 6 points of shield protection. If he did not receive a successful skill roll, he gains no benefit.

Then he receives his damage, subtracting any protection gained from his armor and parry from the damage the opponent did. Any points greater than the armor are subtracted from current hit points, and from the location actually hit. The revised current hit points should be compared with the Unconscious statistic.

The loser must check the total damage done (whether or not any penetrated his armor) against his Knockdown statistic. 5. Movement Phase: characters who didn’t fight may move simultaneously. Everyone moves their first metre of movement at once, then moves the second, the third, and so on. Characters don’t have to move their whole rate, but if they stop, they can’t add the distance later in the phase.


Some conditions may affect the success ability of the fighters. These are, as always,applied to the skill level.

Foe above = -5, foe below = +5: when opponents are separated by at least one but less than two metres of height, this modifier is used. This includes when one character is down on the ground and the other is not. This modifier doesn’t apply to firearm attacks.

Foe surprised = +5 to attacker: a foe surprised includes those attacked from behind, or without warning. This attack is always unopposed, with this bonus.

Difficulty seeing = -10: in darkness, fog, smoke, or other similar conditions, characters are all reduced this amount, unless they make their Awareness roll that round.

Target is moving = -2 to attacker: if the target is moving directly at the attacker, there’s no penalty.

Target is dodging = -5 to attacker: a target who is weaving from side to side moves at half speed, but is harder to hit.

Firing while under fire = -3 to attacker: if you’re under fire (even if you’re not hit), you must make a Cool roll, or your attacks are at -3.

Extra round aiming = +5: taking an extra round to aim a firearm gives an increased chance of the next shot hitting. Additional shots in a burst don’t get this advantage.


Health in Interface is measured through the Total Hit Points statistic of a character. His constitution (CON) is his relative health and resistance to disease. But hit points measure how sick or wounded or well he is.

Subtract points of damage both from the character’s total hit points and from his hit points in the hit location where the damage was taken.

Results of Damage

A character reduced to a quarter or less of his total hit points is unconscious. A character reduced to zero or negative hit points is dying, and will be dead after a number of combat rounds equal to his CON, unless he receives treatment raising his hit points to at least +1 before then.

Damage Equal to or in Excess of the Hit Points for Individual Hit Locations Abdomen: both legs are rendered useless and the character must fall. He may fight from the ground, at a penalty of -5 with any melee weapon. He may not move faster than 1 metre/combat round.

Arm: the limb is useless. If the character was holding something in that hand, it will fall unless it was attached to the arm. The character can continue to stand and act with whatever limbs are left.

Chest: the character collapses, unconscious.

Head: the character falls unconscious.

Leg: the limb is useless. The character falls. He may fight from the ground, at a penalty of -5 with any melee weapon.

More than Double Limb Location Losses

A character cannot take more than twice the hit location damage possible to an arm or leg. At this point, the limb is irrevocably maimed or severed (timely hospital treatment may prevent this).

More than Double Head, Chest, or Abdomen Losses

If the chest or abdomen receive more than twice as many damage points as there are normally hit points in that location, the character will die unless treated within his CONx1 rounds.

If the head received twice as many points of damage as its normal rating, it is severed, crushed, or otherwise irrevocably maimed, and death is instantaneous.


When a character receives a hit, through combat or some other means (such as being run into by a motorbike), the damage must be compared to his MAS. If the points of damage are equal to or greater than the knockdown statistic, then the character has received a blow which sends him reeling for balance.

When unbalanced, the character must receive a successful DEX roll. If he is successful, he does not fall down, and can continue fighting.

Whenever a character receives damage equal to twice or more than his knockdown, he doesn’t even have a chance to make a DEX roll, but always is bashed down.


Armor protects against damage, but only for those hit locations which it covers. Each point of armor worn subtracts one point from any damage the wearer may suffer. Certain types of armor are effective only against specific weapons.


Natural healing is 2 points/week. It’s much faster in a hospital, usually at least 1 point/day.

States of Health

A character’s state of health is determined by his current hit points as compared to his total hit points. Actions may be restricted by his state of health.

Total health: a character has full hit points. No character can ever have more than his total hit points.
Lightly wounded: damage is from 1 point to 1/4 of the character’s total hit points. All activities allowed at normal level.
Seriously wounded: damage is between 1/4 and 1/2 of total. Any strenuous activity, such as combat, stops any healing for that week. Social activity, romantic activity, and travel are allowed without consequence.
Grievously wounded: damage is between 1/2 and 3/4 total hit points. Character is capable of any action, but at 1/2 normal skill level. Any movement stops healing for that week, and incurs one point of damage per day of movement or activity.



A roll of 20 when shooting a firearm means that the weapon has jammed. On the following combat round, the character must make a skill roll with the appropriate weapon skill to unjam the weapon. A success means it can be fired the following round. A fumble on the unjamming roll means that the weapon is permanently broken.

Some weapons (lasers, gauss guns) are more fragile, and break instead of jamming. They may be repairable, but only outside of combat.

If a weapon has a separate component which could be broken (laser sights), roll randomly to determine whether the weapon or the accessory failed.

Example: Johnny Logic uses an EEG patch to pick up the mental signal to fire his smartgun-equipped Magnum 1000. He rolls a 20, a fumble. Either the pistol or the smartgun modification could have failed, so he rolls a d6, odd numbers indicating the electronics. A 3: the GM rules that Johnny’s sweat has loosened the EEG patch, and it’s fallen off. Luckily, there’s still a manual trigger, and the next round Johnny fires again. Another 20! This time only the pistol can fail, so it’s jammed until Johnny can reverse his luck and make a Handgun/Projectile roll.

Automatic Weapons

Automatic weapons can fire multiple shots with one squeeze of the trigger. When firing a burst, you get d6 shots, at half your normal chance. When you shoot at more than one target, each additional target is at -1 to hit.
Example: Rudy Hopper, mercenary for hire, has a skill of 10 and a speed 11 with his Nishimura submachine gun. Facing a gang of senile delinquents, he decides to fire a burst of 3 shots at 3 different targets. His chances and speed are 5/11, 4/10, and 3/9. If he’d fired the burst at the toughest looking geezer, he’d roll at a skill of 5 for each shot, all at speed 11.
Shots fired in a burst can’t critical, but they can fumble. Ignore any shots after a jammed weapon.

Opportunity Fire

Waiting for a target, for example training a weapon on a doorway and firing as soon as someone walks through, is called opportunity fire. It happens at speed +5.

Unaimed Shots

Sometimes you’ll just want to shoot to keep someone else pinned down; you don’t really care if you hit or not. You can take two unaimed shots (or one unaimed burst) per round at speed +5, but at half of your skill. An unaimed shot cannot critical, though it can still fumble.

Firing into a Crowd

If you fire at a tightly packed group of people, such as two people engaged in hand-to-hand combat, you, and you hit, the target is chosen randomly. A critical success roll lets you choose the target or choose a hit location on a random target.

A miss doesn’t generally mean that a bullet missed one person and hits someone else, though it depends on the situation.


Grenades can be thrown (a DEX roll) or fired from a grenade launcher (a skill roll with Heavy Weapon/ Projectile).

Concussion Grenade

Roll 4d6 damage against anyone within 1 metre of the grenade, 3d6 against anyone 2 metres away, etc. opposed roll: damage vs CON (or maybe HP?) If the damage wins the opposition, the target is stunned. In any case, 1/3 the damage will be done to the target’s general hit points, and armor won’t stop this damage.

Flash Grenade

Must roll POW/2 or be blinded

Fragmentation Grenade

Roll 5d6 damage against anyone within 1 metre of the grenade, 4d6 against anyone 2 metres away, etc.

Gas Grenade

Miscellaneous Combat Notes


A character can choose to avoid an incoming blow by throwing himself out of the way. He does this by opting to dodge instead of using his weapon attack and parry. Treat this as a simple unopposed resolution roll, based on DEX. A successful dodge means that the character avoided the blow and remained on his feet. An unsuccessful dodge means that the character fell to the ground. If the enemy’s attack roll succeeds, and the dodge roll fails, then the dodger is hit.

When dodging, a character’s effective DEX is reduced one point for each 3 points of armor worn.

Dodging a firearm is virtually impossible: the roll is made at DEX-10, rather than DEX (but the character falls down only if the roll is above DEX).

Aimed Shot

A shot or blow can be aimed to hit a more (or less) vital hit location. Before rolling for the attack, the attacker declares that he is taking an aimed shot, and decides by how much to reduce both his skill number and speed. If he wins the combat, he can adjust the roll for hit location by up to the same number of points. The adjustment can never be larger than his DEX.
Example: Mona Chrome has a DEX of 13, and a skill of 11 with her Culebra L16 laser pistol. She’s in a firefight with Sally Wire, who has reflective armor covering her body. Mona realizes her best chance is to hit Sally’s head, so she reduces her skill and speed by 4. At speed 8, she rolls a 6, and barely hits. The d20 roll for hit location is 15. Mona adjusts this to a 19, so the laser hits Sally in her unprotected head.

Multiple Attacks

Characters may be attacked in melee by more than one opponent at a time. Up to three may do so on foot.

Defenders may fight against as many attackers as they wish, dividing their weapon skill among them. The skills must be rolled separately on the resolution rolls. Unopposed opponents make unopposed resolution rolls.

Example: Johnny Logic is set upon by three thugs. Johnny decides to divide his Athletics/Fist skill of 12 between the front two attackers, allocating 6 points per attacker. The first thug misses; Johnny rolls a 7 and also misses. Against the second Johnny rolls a 5, under his divided skill; the thug rolls 2, and Johnny manages to punch him. Unfortunately, the thug behind Johnny has an unopposed attack roll, and hits.

Point Blank Range

Point blank range is that number of metres equal to or less than the character’s DEX. It gives half again the normal chance to hit.

Protected Targets

The chance to hit a target behind protection is the same as that to hit an unprotected target. But if the hit location rolled is behind the protection, the weapon fire hits the protection instead of the target. If the weapon is powerful enough to pierce the protection the excess damage still hits the target.

Withheld Blow

Combatants may voluntarily restrain the force of their hit through the use of a withheld blow. Roll damage and figure for knockdown as usual, but no normal damage is done unless a critical success is rolled. A critical success does normal damage, rather than double damage.

Unarmed Combat

When someone with the Unarmed Combat skill wins a resolution with Athletics/Fist or Athletics/Kick, he has the option to roll damage normally, or to make an opposed resolution of his Unarmed Combat skill against the hit points of a random location. If he wins, the location is disabled, stunned for 10 rounds (think of it as hitting a pressure point or “funny bone”).
Example: Lotus Flower, with Athletics/Fist 15 , is still in hand-to-hand combat with the street samurai. She wins the resolution, and decides to user her Unarmed Combat 12. She rolls a d20: 17, his left arm, which has 7 hit points. She opposes her skill of 12 against his 7 point arm. She rolls 2, but is beaten by his 5. The arm takes no damage. If she’d simply tried to damage it, it would have taken the usual d6-1 damage from a fist, and would be easier to disable the next time.
flying tackles, grappling, etc. are the Brawling skill

Last updated 5 Nov 99 drd

David Dunham Page | Interface