Let's Read “Traveller: Core Rulebook - Combat”

Quick and Dangerous with Some Nice Skill Additions

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It seems as though every RPG includes a section on combat. Perhaps this comes from the hobby’s wargaming roots.

At 6 pages, the combat chapter is quite short. And we get a fair warning:

Combat in Traveller is designed to be deadly, especially if there is a gap in technology between combatants.

Traveller: Core Rulebook p70


Everyone rolls adding the higher of their Dex or Int modifier. The book uses the language of Effect. Effect is taken by subtracting 8 from your roll. Technically, if each character had different difficulties for Initiative, then we’d need to consider effect. Personally, I find it easier to convey “Highest roll wins”.

A quick sub-section gives guidance to the referee: You may want to only roll once for all of your forces.

In the case of an Ambush, everyone still rolls initiative. However, the side (or individuals?) that’s aware gets DM +6 to their roll. Those unaware gets DM -6. A 12 point swing guarantees that if you get the drop on an average foe, you’re going first.

An unsurprised Traveller (or opponent) may make a Tactics check at the start of combat. The Effect applies to each member on the side. I find the inclusion of a Tactics check as a welcome addition to initiative. You still want to aim for surprise, but even then fortune favors the experienced.

The rules provide a brief discussion regarding maps. These days, I play all of my games online. I strongly prefer theater of the mind instead of maps. I also prefer quick narrative scenes with desperate and decisive combat. But that’s for another time.

The Combat Round

Each round is 6 seconds. Each round, on their turn, a Traveller may make a Minor Action and a Significant Action. Interesting, based on the Multiple Tasks rules, I would’ve thought characters would get more than one action.

Significant Actions

Most often, in combat, this would be an attack. I’d imagine if you were trying to do something athletic that would count as a significant action. At this point, I wouldn’t allow multiple attack tasks but I would allow multiple tasks as part of one action.

A Traveller can skip their significant action to perform two additional Minor Actions. Well I may have spoke a bit too soon about multiple tasks.

It could also be a skill check, issuing a command, or calling in an air/orbital strike.

With an explicit rule about multiple tasks, I would certainly allow multiple tasks as a significant action.

Minor Actions

Aiming, moving, reloading, drawing a weapon, standing, crouching, lying down, or some real minor task.

Free Actions

A quick shout. Or pushing a button.

Extended Actions

For tasks that span multiple rounds, while you are performing tasks, when you sustain damage you must immediately check that skill. Any damage you sustain counts as a DM penalty.

Failure means your effort for the round doesn’t count towards the total effort. Failing with an Effect of -6 or less ruins the task.


As a Signficant Action, your Traveller can make a Leadership check. On a positive Effect, the leader grants a number of Boons to other Traveller checks. On a negative Effect, the opposing side may inflict a number of Banes equal to the Effect.


A Traveller under attack may react by dodging, parrying, or diving for cover.

Each reaction imposes a DM -1 on their next set of actions.

Dodging imposes a penalty on an incoming attack. The penalty is the better of the Traveller’s Dexterity or Athletics (dexterity). Every attack must be dodged. You can dodge both melee and ranged attacks.

Diving for Cover only works against ranged attacks. And depending on whether there’s objects or simply dropping prone the penalty to all ranged attacks is DM-2 and DM-1 respectively. When diving for cover you forgo your next action.

Parrying works against melee attacks. You apply a penalty to an incoming melee attack equal to your Melee skill.

Characters within 2 meters are locked in combat. They may only attack those in their close combat group. You can fire single-handled ranged weapons, which can be parried. Rifles can be used as clubs. And moving away provokes a free attack with DM+2 to the attack roll.


This section gives a quick rundown of weapon attributes.


Add the Effect of an attack to the roll. A nice add the better you are the more damage you do.

Apply damage to END. Any excess reduces STR or DEX. If either STR or DEX drops to 0, your Traveller’s unconcious. If all three physical traits drop to 0, you Traveller’s dead. The example damage of a Rifle is 3D. This would make combat quite dangerous.

STR adds damage to melee weapons. Armor reduces damage, though some weapons have armor piercing.

Cover imposes penalties to attacks and can provide bonus armour.

Destructive Weapons

Some weapons are destructive. When you roll damage, you multiply it by 10.


Make opposed Melee (Unarmed) checks, and the winner may choose from a menu of options. Drop them to the ground, disarm (and maybe take a weapon), throw an opponent, inflict melee damage, inflict weapon damage, drag the opponent, breakaway, or continue the grapple.

Dual Weapons

Here we have a callback to Multiple Tasks. You can attack with two different weapons, each at DM -2.

So, I’d definitely say that you can’t use a weapon to attack more than once per combat round.

Weapon Traits

Lots of different traits for weapons.


And that wraps up Combat. Its quite clear that combat is a dangerous affair. Travellers have numerous options; I’m particularly fond of Tactics and Leadership having a mechanical bonus.

Up next Encounters and Danger.