Cascading Dice: A House Rule for Tracking Ammunition

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Dice-tipped Arrows

The Green Arrow's got nothing on Team Intwsicha

Arrows, O how I hate counting thee!

Whether the game is B/X D&D, Shadowrun, or 4th Edition D&D, players have for years forgotten to keep good track of mundane consumables like food and arrows. Why?

It just ain’t fun.

More important numbers like hit points are fun to keep track of, because hey, if they’re gone, you’re dead. And while the same is theoretically true about food, it just doesn’t have the same pizazz as more potent numbers like spells per day.

However, the alternative is usually not fun, either–simply ignoring consumables. After all, it is fun to (every once in a while) be stuck in the wilderness, unsure of where your next meal is coming from–or ducked down behind a barricade, trying to figure out how you’re going to deal with the gang bangers when all you have is an empty gun.

Somewhere along the line, I encountered a Wild West game that had a simple ammo rule: every time you shoot, roll a d6. If you roll a 1, you’ve fired your last shot. We used that rule in a recent Gamma World game, and it seemed to work. However, it’s pretty unforgiving. Furthermore, it doesn’t always make sense: while it might work in a shootout at a remote location, it doesn’t fit as well if the characters are well stocked.

This brings us to…

Cascading Dice Ammo Tracking

The GM picks a type of die (d12, d10, d8, etc…) based on several factors, which we’ll explore below. This represents full ammo for that scenario–so a player might record on her character sheet: “Ammo: d12.”

When a player rolls a “1″ while using a firearm, the die type decreases by 1 type. So, a d12 becomes a d10, a d10 becomes a d8, et cetera, down to the lowly d4.

When a player rolls a “1″ on a d4, she has one arrow left.

At the end of a combat when ammo has been used, the player drops to the next die type. In the example given, if the player began with a d12 and never rolled a 1, she would use a d10 at the next combat. If the character is able to find a stash of ammo through the course of adventuring, she may increase a die size. And if a character is able to “get back to town” (that is, get a reliable supply of more ammo), she may immediately jump back up to an appropriate carrying limit as the GM decides.

Adding color to the crunch

Arrow StackAbstractly, this system represents a character possessing a relative level of a consumable. For instance, using a d12 with ammo represents an average of 40 arrows, but it could be as few as 5 (for the unlucky bastard who rolls all ones: 0.0043% chance when starting with a d12!), or more than 100 (in 1,024 rolls starting with a d12, only 5 were lucky enough to fall in this category).

But what does it actually represent?

To illustrate, let’s go back to the 1e “combat round” that took a full minute. The idea was that the attack roll represented the success of a minute’s worth of effort–this could be one telling sword swing, but probably was a dozen exchanges before a good meaty thunk.

Why not do the same with arrows? Some rounds, you might get one arrow off, and others might be a barrage of 5 or 6. Other times, in the heat of combat, you’re just not keeping a very close watch on your arrows, but in a moment, you’re surprised by the lightness of your quiver. These situations are what happens when you roll a “1″ and go down to the next die size.

When you’re down to a d4, you’re going to be a lot more careful with ammo than you were when you used a d12.

What die to use and when

To get an average number of shots, simply add the values of the die. Using a d12 (12+10+8+6+4) gives an average of 40 shots, whereas using a d8 (8+6+4) gives 18 shots.

The d12 feels like a good starting number for GMs who allow their characters to carry 40-ish arrows. If you’re more of a 20 arrow kind of person, go down to an 8 (18 shots) or 10 (28 shots). In a “defend the castle” situation, where there are plenty of arms available, you might even use a d20 to start with.

Optional rules

  • Want to share ammo? No problem: “crack” the die. A player may voluntarily drop a die size to increase an ally by a die size (for instance, Rowan has d10 arrows left, and Johanna is down to d4. Rowan voluntarily drops to d8 in order to increase Johanna to d6.)
  • Don’t just use this for ammo–it works for food, too! Characters can roll once per day–a 1 represents either that they’ve eaten a lot, or that some food has spoiled, etc… Successful hunting lets characters skip rolling for a day, and something like the “purify food and drink” spell might allow characters to increase the die (go from a d6 to a d8, for instance).
  • This works well for arrows, but is a bit harder for guns that have a limited number of shots before a reload. If you worry about reloading in your adventure, my suggestion is to keep track of your clips and use this system for bullets in the gun (using a d6 or d8)

4 Comments

  1. avatar Chase

    It’s funny, I was thinking of a similar idea in our last game. I can never remember to mark off each shot.

    Even if you’re not actually carrying 41 arrows, starting at a d12 can simulate retrieving them after they’re shot. The randomness could be your inability to find them (arrows are REALLY hard to find in the wilderness), wear or breakage from shooting, or simple attrition in the quiver (nock broke, fletchings got wet and fell off). People tend to underestimate how fragile bows and arrows are.

    Using this system in a game, you could do purchase and encumbrance by the die. So a d12 of arrows costs X and weighs y.

  2. avatar Matthew
    Posted 05/18/2011 at 10:22 am | Permalink

    I did seem to be reminding everyone quite often to mark of ammo. But then again I had to remind everyone to mark of torches, oil, and rations also.

    Would this rule work for all consumables?

    If someone wants to put together a chart matching die size to arrow cost / and weight in stone we can give this a try for the next foray into the wilderness

    • avatar Chase
      Posted 05/18/2011 at 11:01 am | Permalink

      As it turns out, 40 shots is about what you get if you start with 20 arrows, and assume a 50% chance of recovering each arrow: 20+10+5+2.5+1.3+0.7. I think a d12 of arrows is exactly the same as a 20 arrow quiver.

      • Posted 05/18/2011 at 11:24 am | Permalink

        Awesome! I knew it intuitively felt right, I’m glad to see that the math works out.

        This means that a d20 (60 shots) is roughly a 30 arrow quiver with 50% breakage.