C.A.T.S.Crunchy Automated Tactical System

Hit Location

Location is rolled on an exploding d6. Critical systems are unreachable without an explosion.

You have to explode to hit something vital

A single exploding d6 partitions itself into exact tiers of five, separated by the unreachable multiples of six. Reaching tier n requires n−1 explosions. No table design was involved — the die does this on its own.

Hit location by depth: reaching a deeper layer requires that many explosions.Tier 1: 83.33% of hits, needs 0 explosionsTier 2: 13.89% of hits, needs 1 explosionTier 3: 2.31% of hits, needs 2 explosionsExternal structure — limbs, hull83.33% of hitsInternal systems13.89% of hitsCritical systems2.31% of hitsno explosion1 explosionExplosion punches through layer 12 explosionsExplosion punches through layer 1Explosion punches through layer 2Layer sizes drawn for legibility; the percentages are exact.

A shot that never explodes stops at the outer structure. Each explosion punches through one more layer. Depth is not something a gunner aims for — it is something the dice grant, which is why armour and depth are the same idea.

Share of hits by tier

Tier 10 explosionsTier 1: results 1-5, 83.33% of hits83.33%External structure — limbs, hullTier 21 explosionTier 2: results 7-11, 13.89% of hits13.89%Internal systemsTier 32 explosionsTier 3: results 13-17, 2.31% of hits2.31%Critical systemsTier 43 explosionsTier 4: results 19-23, 0.39% of hits0.39%Catastrophic
TierResultsExplosions neededShare of hits
11–5083.333%
27–11113.889%
313–1722.315%
419–2330.386%
525–2940.064%

Tier shares form an exact geometric series summing to 1: 5/6, 5/36, 5/216, 5/1296.

Why this is the right mechanic

Design goalHow depth tiers serve it
Layered protectionArmour, then structure, then components. The die now models that directly
Playable damageA unit takes many outer hits before anything vital is touched, so it degrades progressively
Critical means criticalAn explosion is already the critical mechanic. Now a critical result literally finds something critical
Bounded bookkeepingFive entries per tier, and most hits never leave tier 1

Known risk

Tier 1 absorbs 83.3% of all hits across just five locations, so those locations must be armoured for saturation rather than an even spread. And at 2.31%, a critical hit lands roughly once every 43 hits — dramatic, but possibly too scarce to shape tactics. Buying depth with Margin is the obvious lever.