TTRPG Consumable Design: When One-Use Items Break the Rules

Robert Zu Lee has a grenade.

That sentence shouldn’t be a design problem. But the moment I put it on his character sheet, I had to answer a question I’d been quietly avoiding: how do consumables work in a system built around quality / durability?

The obvious answer arrived fast, as obvious answers do. Grenades are one-use items. Give them a use counter. ND = uses remaining. D6 grenade = three throws. Use one, it’s a D4. D0 = empty.

I said no immediately, and then had to think hard about why.

It wasn’t that the idea was broken. It works, technically. The problem is what it implies: a second definition of ND, reserved for a specific item category. Once you do that, you’ve created “consumables” as a mechanical class that plays by different rules. That’s how you end up with page 47 of the Explosives Supplement that nobody reads and everyone forgets mid-session.

I want one system. I repeated that three times during this design process. The ND on your armor means quality / durability. The ND on your knife means quality / durability. The ND on Robert’s grenade has to mean quality / durability too. Full stop.

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So what does a grenade’s ND actually represent, if not uses?

Quality. Durability. Manufacturing grade. How reliable the fuse is. Whether the initiator survived six months in a field pack. A D6 grenade is decent surplus — functional, predictable, but not military spec. A D10 grenade is engineered to perform. A D2 grenade is something you found in a collapsed supply cache and you’re not totally sure about.

With that framing locked in, the degradation logic follows naturally: the grenade degrades 1 ND per use. Not because it’s a consumable, but because using it — detonating it, exposing yourself to the blast radius, handling it under stress — degrades the cache. The ones you touch first are the ones you trusted first. What’s left is always slightly worse.

That’s the rule. It lives in the Notes column of the table. One line.

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Here’s what made it click as the right solution:

It’s not actually specific to grenades.

That same “degrades 1 ND per use” note appears elsewhere in the system: on certain modules, on specific items that stress hard on activation. It’s not a consumables rule. It’s a modifier that lives in the Notes column for some entries, the same way “Zone” or “Restrictif” live there as effect tags. The system didn’t create a new category. It extended an existing pattern.

That’s the distinction that matters. A category is a structural exception, it needs its own rules, its own lookup, its own mental slot. A note is a clarification. One is overhead. The other is just… the table being readable.

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Let me run the actual play example.

Robert throws the grenade. Because it covers a zone — multiple targets — the roll gets advantage for using this piece of gear. He succeeds. Every target in the blast zone takes 1d10 damage. Then the grenade’s ND drops from D6 to D4.

That’s it. No special resolution. No “consumable tracker” sidebar. The GM checks the table, sees the Note, applies -1 ND. Moves on.

At D4, the remaining supply still works. At D2, you’re throwing something improvised and hoping. At D0, it’s gone, or it fails on use, which is its own kind of tension. The quality degradation creates a natural arc: the grenade gets worse before it disappears, and that progression is meaningful in a way a binary “uses left” counter never is.

Imagine jumping around with a D2 grenade at your belt. On another game it would be Grenade x1. Here with a consequence, with a ND drop on the grenade without even using it, it could mean shit is gonna hit the fan. I want that kind of tension and stress at a table.

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I’ll be honest about one thing: my first instinct after rejecting the use-counter was to build a clever metaphor around it. The “cache quality” framing — the ones you touch first are the ones you trusted most — felt elegant. And I held onto it for longer than I should have, because it was narratively satisfying.

The actual solution is simpler and more honest: ND = quality, degradation trigger = per use, lives in the Notes column. No metaphor required. The table communicates it directly.

This is something I keep running into with Sol Fracta‘s design. I’m drawn to elegant framings. Sometimes they reveal a real mechanic. Sometimes they’re just a way to make an overly complicated solution feel justified. The test is: does removing the framing break anything? In this case, no. The mechanic stands on its own. The narrative emerges from play, not from the explanation.

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The cost of the uniformity commitment is iteration. I went through at least two framings of this before landing here. The benefit is what I get at the table: when someone picks up Sol Fracta for the first time and asks “how does the grenade work?”, the answer fits in a sentence. Same ND system as everything else — check the Notes column for the degradation trigger.

No page 47. No exception to remember. One system that handles armor, melee, ranged, explosives, and modules with the same underlying logic — sometimes with clarifying notes, never with structural exceptions.

Robert’s grenade starts at D4. Use it well.

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In your TTRPG consumable design, where’s the line between a note that clarifies and a rule that creates a category?