Combat in 24XX

If your experience with RPGs comes mostly from D&D, I can imagine you might be a little confused upon reading 2400, or any of various 24XX RPGs by others. In fact, I’ve already fielded a few questions from people wondering where did the hit points go? I tried to address this briefly in the Emergency Rules (available free on and DriveThruRPG), but I figured a longer example might be helpful, especially for those working on their own 24XX games.

The 24XX SRD doesn’t really have “combat rules”; it has rules for facing and mitigating risks. (Individual 2400 or 24XX games could certainly offer some, though!) By the rules in the SRD, when you try to avoid a risk, you roll some dice based on your skill and circumstances, and take the highest. On a 1–2, there’s a disaster—you suffer the full consequences of the risk. (That doesn’t necessarily mean you “fail” your action, though! Just that you don’t avoid whatever you were trying to avoid.) On a 3–4, there’s a setback—you suffer a lesser risk or achieve only part of what you meant to achieve. On a 5+, you get what you want, no risk. And if you roll really poorly, you can sacrifice an appropriate item (usually armor) to avoid the risk you would have faced, instead facing only a brief hindrance. It’s the GM’s job to advise of risks, and of your (apparent) possible effectiveness, before you roll. Different situations have different risks, and different scope for how much you can accomplish for one roll. You establish the details as you go, as an improvised conversation.

With that context out of the way, all of the following examples are valid “combat encounters” by 24XX rules.

Risking nothing

PLAYER: I shoot him with a tranquilizer dart!

GM: Okay. He couldn’t see or hear you, so there was no particular risk. He grabs where the dart stung him, reels a moment, and slumps over, unconscious. What do you do next?

Risking death

PLAYER: I shoot him!

GM: Okay, but he could shoot you back. You’d be risking death.

PLAYER: Whatever, I have d10 in Shooting.

(If the player rolls a 3–4 when risking death, the character will be grievously injured, likely maimed. But the player rolls a 2—the character is going to die. The GM could say this this means the character is killed before getting a shot off, but that feels a little anticlimactic, so the GM opts to have the character go out with a bang.)

GM: The bullet catches you in the chest, but not before you pull the trigger. Your opponent clutches his neck and his eyes widen. And as for you—any last words?

PLAYER: I chuckle and say, “Well, dang,” then slump over, still wearing a smirk.

GM: Nice. Make a new character—the rest of the characters will meet them in the next room.

Mitigating risk

PLAYER: I shoot him!

GM: Okay, but he could shoot you back. You’d be risking death.

PLAYER: Can I shoot from behind cover?

GM: Yeah, the risk would be less that way—maybe hitting your hand or grazing your head, but let’s say there’s no risk of death. You’re probably not going to be able to get any precise shots off this way, though.

PLAYER: That’s okay—I just want to lay down some cover fire so they don’t rush us.

(The player rolls a 9—higher than needed, so the GM decides to throw in a bonus effect.)

GM: Nice roll! You hear someone shout out in pain—sounds like you actually hit somebody. You can’t make out exactly what they’re saying, but it sounds like the others are staying put and administering first aid.

Facing a tough opponent

PLAYER: I punch the alien.

GM: Ooookay. It’s 3 meters tall, with massive claws. If you get that close to it, it’ll probably kill you. What do you hope to accomplish?

PLAYER: I wanna knock it out!

GM: It’s too big to knock out. The most you could hope to do is buy some time for your friends to run away.

PLAYER: That’ll do!

(The player rolls a 3—a setback, not a full success or full disaster.)

GM: Okay, you punch it and feel its claws tearing at you. You’re bleeding bad, but you might live if someone can administer first aid quickly. The alien is off balance enough that your friends could run away—but if they do that, they can’t save you.

PLAYER: But wait—I have armor!

GM: Ah, good! That’s a “defense”—you can say that it’s broken and that the alien just knocks you off balance for a moment.

PLAYER: Yes please—I want that! 

GM: Okay! The claws ripped through your clothes so badly you thought you must be bleeding to death, but thankfully, instead you see your armored vest fall apart in tatters. Phew! Your friends are escaping already, and you can try to get away too, but the alien will be hot on your heels….

Ganging up

PLAYER 1: I push him over!

PLAYER 2: I’ll crouch behind him!

GM: Okay. Sounds like a Hand-to-hand roll, helped by … I dunno, do you have any skills that seem relevant to quickly crouching behind someone unnoticed?

PLAYER 2: Stealth?

GM: Sure, why not. The risk here is that he keeps his balance and starts attacking. Roll when ready.

(Player 1 rolls poorly, but player 2 rolls very well. Since they’re ganging up, this counts as “helping,” rather than each rolling to avoid separate risks, they take the highest die, knocking the target over. If they both rolled poorly, the target might’ve whacked either or both of them, and/or not fallen down at all.)

Mass combat

GM: You’ve got an army at your back and another bearing down on you. Describe what you’ll be doing during this battle.

PLAYER 1: I man a gun turret to defend against aerial attackers.

GM: Okay. Get ready to roll Shooting, and take a d6 help die for superior firepower. The risk is death—either yours, or those of allied forces.

PLAYER 2: I’m in the medical tent, getting ready to treat the wounded.

GM: Okay. You don’t have to roll anything just yet. We’ll come back to you.

PLAYER 3: I’m at the front line, rallying the troops.

GM: Great. Get ready to roll Inspiration. The risk is death or desertion among the troops. Everybody roll.

(There are no formal mass combat rules, so the GM is kind of making it up as they go. They want it to feel like a climactic battle, so they’ve decided that it won’t end after this series of rolls; they’ll do three series, and see how things look after each. For this series, Player 3 rolls a 4—the GM describes the ground troops shouting a battle cry, but some clearly still look terrified. Player 1 rolls a 7—the GM describes an enemy fighter craft crashing onto its own side’s troops. Player 2, in the medical tent, hears the sounds of battle not far off, and sees some deserters fleeing already, before being interrupted by a pair of medics carrying in someone with bad burns. The GM asks again what everyone plans to do.)

Additional considerations

My design goals for the 24XX rules did not include making an excellent tactical combat game—but it’s quite good at quick combat scenes with a lot of variety, that don’t get bogged down back-and-forth attacks and misses. Everything comes back to how you describe things. Weapons, for instance, don’t have “damage” ratings, but are generally self-evidently different in function: The examples above would have each been totally different if you swapped out whatever weapon had been described for a different weapon.

Given all that, the above scenarios are examples of how I might run combat, but they’re not gospel. It’s not an accident that multiple examples specify there aren’t specific rules for this, so the GM made it up. That, after all, is actually written into the rules. 24XX demands a lot of improvisation from GMs and players, so we have to expect that different groups will play the game pretty differently. But if you were approaching the game and scratching your head in confusion before, I hope this helps clarify what life without hit points looks like.

Banner art by Beeple (Mike Winkelmann).

5 thoughts on “Combat in 24XX

  1. As I continue to gain experience running 24XX, the disaster / tough choice / success/ extra thing gets easier and easier to figure out. The key thing for me is that 24XX combat is _scary every time_ and there are no guarantees that a player character can survive even the first touch. Make sure your players get that well before they decide to keep forward into a brawl.

    1. It can be scary! But it can also be not very scary at all, depending on how you define the risk before rolling. If characters are careful, the risk might only be “superficial wounds” on a disaster and “losing your footing” on a setback. I try to use “you risk death” only for things that are pretty darn likely to kill you if you are reckless.

  2. Really inspiring! Thank you very much, sir.

    Just one question about rolls… If a character is hindered (situation, pain, horror…), does they roll a d4 or a worse die (from d12 to d10, for example)? Thank you!

    1. Thanks! Being hindered means they roll a d4 instead of their skill die. I don’t like fiddling with modifiers or changing dice sizes one step at a time, so I made the rule to just jump right to the lowest die (much like the “impaired” attack roll in Into the Odd). This makes a full success impossible unless they have help. (You CAN be helped AND hindered, so you’re rolling a d4 hindered skill die from a disadvantage, and a d6 help die from an advantage.)

      You’re free to run it however you like, of course! But I hope going over the intent helps clarify why it’s designed the way it is.

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