A Star Wars combat effects system for Mythras

This is a combat effects system built for a Star Wars campaign I thought of running, using the Mythras game, but designed to shift the combat effect choice to place it before the dice are rolled, rather than after the die roll (as is the case in the default Mythras rules). This better suits my player’s preferences and my own understanding of the OODA loop. While our next campaign will have a renaissance theme, rather than use the Star War setting, the ideas here will influence the combat system I am planning for that. This builds on some rules in an unofficial Star Wars rules for Runequest 6, and information on the Wookieepedia.

Some assumptions:

  • Hit Points will be at Pulp Cthulhu levels, general HP, no location HP.
  • Roll on a serious wounds table if you lose half your HP in one attack, or drop below 0 HP.
  • Initiative used the Fast/Slow actions from Shadow of the Demon Lord.
  • Most blaster weapons do 3d6 to 4d8 dice of damage, while most lightsabres do 3d12 damage.
  • Armour works by first removing dice, one die per point of armour, then by reducing the last die, one point per point of remaining armour. For example, a Heavy Blaster (3d8) is used against someone in heavy armour (five points), the dice roll 1, 5, and 8. The first two points of armour discard the 1 and the 5, the remaining three points reduce the 8 to five points of damage.
  • Light, medium, and heavy armours have one, two, and five points of armour respectively. Medium armour reduces Athletics skill by /2, Heavy armour by /5.
  • Light, medium, and heavy shields have one, two, and five points of armour. Medium and heavy shields are harder to conceal. Once a shield stops a hit, it has no further effect until you survive a combat round without being hit. Shields are working more like the computer games than in other Star Wars media. The campaign was going to be set centuries after the movies.
  • Use Advantage/Disadvantage dice rather than modifying skill levels for situational and environmental factors.
  • “Mastery” was going to be a skill progression mechanic that extended the die rolls on which you scored critical hits – which I suspect in practice would require a bit more time in play, and take up a lot of character sheet real estate, so its not a concept I am sure would have worked.

This is not a set of mechanics I have tried at the table!

Combat Traits for Non-Lightsabre Weapons

For non-lightsabre weapons, choose one of the following traits for each of your professional combat styles:

  • Cavalry: you are proficient using your weapons while mounted on a riding beast or vehicle – your combat style skill is not capped by your ride or pilot skills.
  • Concealable: you are proficient at concealing your weapons from view or casual inspection and have advantage on any Stealth checks required.
  • Enforcer: you are really good at setting your blasters to stun, with targets getting disadvantage on their Endurance checks.
  • Heavy Weapons: you can sunder armour with heavy weapons, your damage dice are reduced to one point rather than being discarded by armour.
  • Martial Arts: upgrade your unarmed combat die to 1d12.
  • Sidearms: you are proficient at getting in the first shot, drawing and firing your weapon is a free action with double advantage in the first round of a combat scene.
  • Skirmisher: You can do a partial move on a Fast Action (equal to Athletics/5).
  • Sniper: you are capable of precision targeting, even with a blaster, and can aim with your first attack each turn (gain an advantage die).


You do not have to be a force user to use a lightsabre, as this weapon was popular during the golden age of the New Republic, and is favoured by nobles and assassins. Rather than choosing a combat trait, for every 20% skill with lightsabres, take one of the following forms:

  • Shii-Cho: on a successful attack, you can attempt to disarm your foe, or sweep – make one attack (with disadvantage) against each foe in melee range.
  • Makashi: on a successful attack, you can impale your foe (counts as a major wound if you do at least one HP of damage), or overextend them (disadvantage on their next action). An impaled weapon is trapped in your foe’s body and requires an action to remove.
  • Soresu: allows you to parry blaster fire (and deflect back on a critical success), or to arise from the ground as a free action.
  • Ataru: on a successful attack, allows you to ignore a point of armour, or to make a second attack (with disadvantage).
  • Shien: allows you to parry blaster fire (and deflect back on a critical success), or to parry and make an Acrobatic leap.
  • Djem So: on a successful attack, knock your opponent back, or impose disadvantage on their next attack roll.
  • Niman: when using two lightsabres, on a successful parry you can pin an opposing lightsabre to make it unusable until freed, or make a free attack.
  • Juyo: on a successful attack you can attack again if parried or evaded, or increase your damage by +1 for each other form you have learned.
  • Vaapad: this form has Juyo as a prerequisite. Your Acrobatics mastery is included with your Lightsabre mastery for the purpose of determining critical success, or spend Force Points equal to a damage die roll to bypass armour (e.g. if you rolled 5 and 7 versus one point of armour, spend five force points to inflict 12 damage rather than seven damage)
  • Lus-Ma: allows you to interrupt and make a free attack against someone rising from the ground, or to use a slow attack to ignore all shields on a target.
  • Sokan: if exploiting high ground, gain double advantage, or make an extra movement action (to a maximum distance of Acrobatics/5).
  • Jar’Kai: when using two lightsabres, either forgo defence and two strike as one (both weapons hit on a single attack), or forgo your attack and parry with both weapons, with each critical success parry allowing another free parry.
  • Trakata: this form exploits quickly turning your lightsabre off and on again, when attacking forgo your ability to parry to ignore one enemy parry, or to force you opponent to stumble, granting you advantage on your next attack.
  • Zero: before a duel begins, use this to gain advantage on a single skill check of your choice (e.g. a Persuasion check to prevent the fight, a Perception check to identify the form your foe is about to use, etc). If you know five or more other forms, gain advantage on your first action in any duel.
  • Stanzi: a form that exploits the reach of Force Pikes, allowing you to interrupt a fast attack from someone with a shorter weapon with your attack action for the round. This can be combined with a slow action.

Using the same form in two successive rounds grants your opponent’s advantage on attacks and parries against you. If you use it for a third successive round, they gain double advantage. You must choose your form before rolling the dice for an attack, otherwise you are assumed to be repeating the last form you used.

In most force or dueling traditions, Shii-Cho is the first form taught, followed by Soresu or Shien. Ceremonial Guards are more likely to be taught Stanzi. Juyo and Vaapad are only taught by force traditions that take inspiration from the Sith.