Die, Usage Die

Back in the bad old days, we walked to school. Uphill. Both ways. Barefoot.

And damnit, we hated it, but it was good for us.

We also counted: iron rations, individual arrows, throwing daggers, healing potions, how many feet of rope we carried, and individual copper pieces. Yep.

And damnit, we hated it, so… eventually everyone in the entire industry pretty much just gave up on that shit.

Tracking individual consumables is one of those design problems that’s been “solved” about fifteen different ways, and most of the solutions are worse than the problem. My latest TTRPG work, CORPSEC, had a usage die for ammunition. The Black Hack-style degrading die: d10 steps down to d8 steps down to d6, and so on, and you roll it at the end of every round you fire. It degrades on a 1 for single shots, 1-2 for burst. Suppression fire auto-degrades. Walking fire degrades twice. And when you finally hit empty, you spend an action to reload.

In playtesting, three problems surfaced immediately.

Usage Die Wut? Here it is, the end of the round, and everyone’s figuring out positioning for next turn. “Oh wait, ammo die.” Every. Single. Time. This disconnected, separate, odd little roll that lives outside the flow of combat. Immersion crushing and very often forgotten.

Glacial. A single-shot attack is a 10% chance to step down from a d10. Do the math on that curve. You can fight for eight, ten rounds before the die even moves. No combat in CORPSEC has lasted more than 5 rounds. Bullets are deadly and people are squishy in this game. The mechanic promises tension and never delivers it, because it’s on geologic time.

Who Cares? It only takes one round to reload. Your PC is part of a mercenary team, so the rest of the squad keeps firing. You skip a beat. Whoop dee doo. The consequence was so mild that even when the die finally degraded all the way down, the moment of running empty was a non-event.

The Black Hack usage die is a perfect example of a mechanic that’s elegant in description and mediocre in play. It reads beautifully. “Roll your die, on a 1-2 it steps down.” You can explain it in ten seconds. Designers love it because it’s clever and compact and it sounds like an innovation: a third path between “track every bullet” and “don’t track at all.”

It’s “don’t track at all” wearing a hat.

Lordie, for a couple of desolate years, the OSR-adjacent community copy-pasted this thing across every possible application. Spell slots. Torches. Rations. Arrows. Morale. If it could deplete, someone stuck a usage die on it. The fanboys cooed and applauded. Nobody asked whether the die was actually creating decisions at the table. It wasn’t. It was spreadsheet bookkeeping disguised in a random number generator.

What T2K Gets Right

Twilight: 2000 (the Free League 4th edition) solves ammo tracking by making it part of the attack roll. Each weapon has a Rate of Fire. When you shoot, you can throw additional d6 “ammo dice” alongside your skill check, up to your weapon’s ROF. A 6 on an ammo die gives you extra damage, extra hits, or suppression. Two or more 1s jam your weapon. And after the roll, you sum all the ammo dice and that’s how many rounds you just expended from your magazine.

The elegance is that there’s no separate ammo tracking. There’s no “now remember to roll.” The ammo dice are woven into the thing you’re already doing: rolling to hit. And the decision is real. Do I roll conservatively and save rounds, or dump dice and risk a jam?

But, even T2K has a tuning problem. Some groups found the risk-reward calculus didn’t favor ammo dice and just stopped rolling them. Plus, the consequence of actually emptying a magazine, while costlier in T2K’s tight two-action economy, ultimately depends on campaign-level scarcity to do the heavy lifting. In a post-apocalyptic wasteland where every bullet is precious and resupply is near-impossible, reloading hurts because you might not have another magazine. The tactical moment alone wouldn’t be enough.

CORPSEC is a different animal. There are portable 3D printers. It has a quantum equipment rule that means you have stuff unless you don’t. Campaign-level ammo scarcity is genre-incoherent.

So the tactical moment has to carry the weight by itself.

The d20 Was Already Doing the Work

Here’s the fix. CORPSEC uses a d20 roll-under system, with a skill cap of 16. Anything above 16 is already a miss. The numbers 17-20 are dead space on the die. (Mostly. 20 means a miss and “something bad happens” and you get 1 XP. But that’s not the point.)

17-20? Dead space no more.

Now 17-20 is the danger zone. When you roll in this range, the GM decides whether the fiction says you’re out of ammo or your weapon jammed. (Probably not on the first round of a firefight. But six rounds deep into a running battle? That 19 means something.)

The threshold shifts with fire mode. Single shot: only 20. Burst: 19-20. Suppression: 18-20. Walking fire: 17-20.

That’s it. That’s the whole rule.

There’s no extra die, no end-of-round homework and no degradation ladder. You’re already rolling a d20 to attack. Just read it.

Taking a single shot gives you 5% per round. You can fight for a while, but a long engagement catches up. Walking fire is 20% per round, meaning you’re almost certainly clicking empty in a few rounds of spraying. That underlines the meaningful choice between disciplined shooting and emptying clips.

The GM judgement matters. “Jammed” gives them a fiction-appropriate option even early in a fight. Guns jam. Especially cheap Frontier Fabrications garbage. Especially subscription weapons with expired firmware. The Shimada Kiri already jams on 14+ Firearms checks. This slots right alongside existing weapon reliability fiction.

Where the Teeth Are

The thing I got wrong initially was looking for a clever consequence at the moment of running dry. What meaningful decision does being out of ammo create? I chewed on that. Roll to reload? Accumulated Effort to reload? Somebody else has to throw you a mag?

Then the answer clarified: the meaningful decision was already made upstream. It was made when you chose burst instead of single shot. The decision isn’t “what do I do now that I’m empty.” The decision is “do I risk burst fire knowing it doubles my chance of running dry?” That’s where the player skill lives. That’s the game-y part of the game.

Playtesting bears this out. My ruthless kids (yep, playtesting with my kids, the most brutally honest focus group available) naturally gravitate toward burst fire because +10 damage is juicy even with disadvantage on the roll. They’re already making the tradeoff. They feel it. The ammo die never produced that feeling because the consequences were too slow and too disconnected to inform the decision that mattered.

So, I kept the consequence of being out of ammo simple. Reload eats your action. In CORPSEC’s single-action economy, that’s your whole turn. Not a half-turn like T2K’s two-action system. Your whole turn. You’re standing there reloading while someone’s shooting at you. But you chose this, four rounds ago, when you went full auto because the damage was too tempting.

But there’s one more bit of frosting on the cake. Every reload costs 1 LC.

Not as the in-combat sting. You were right (I told myself, arguing with myself during playtesting, as one does): saying “you now owe a hundred bucks” while someone is shooting at you is a big who-cares moment. The LC cost hits later. During downtime. When you’re staring at your Liquidity and trying to make the mortgage payment and you blew through six reloads because you couldn’t stop bursting.

Now the crew’s trigger-happy member is a financial liability. Diego dumping magazines on full auto isn’t just tactically questionable. It’s why everyone’s eating synth protein this month. And that Jaffna Pulse Rifle with no ammo and a 4 LC/week subscription? Suddenly that flat rate looks like a bargain if you can’t keep your finger off the trigger.

The entire combat system connects to the economic engine. Plus it’s pretty simple. One sentence in the reload rule does it.

What I Learned

CORPSEC’s ammo usage die had a detection problem, not a consequence problem. The trigger mechanism was wrong: disconnected from the action, easy to forget. Once I found a trigger already embedded in the attack roll, the existing consequence (lost turn + LC) turned out to be enough.

Genre drives mechanics. Always. T2K’s ammo dice work because scarcity is the genre. Every bullet is precious. The campaign makes the tactical moment matter. CORPSEC’s genre is economic precarity, not material scarcity. So the ammo system had to connect to money, not to counting bullets. The d20 threshold generates the tactical moment, and the LC cost connects it to the economic spine.

And sometimes the state of the art is wrong for your game. The usage die is probably the single most praised indie mechanic of the last decade. It works fine for torches in a dungeon crawl where the consequence of darkness is genuinely terrifying. It does not work for ammo in a tactical firefight where the consequence of empty is mild and the degradation is slower than the fight. Playtest your darlings. Kill the ones that don’t perform.

Die, usage die. Long live the d20.