How does the Wound Roll work in Warhammer 40k 10th Edition?

Compare Weapon Strength (S) against Target Toughness (T): If S is double T or more, wound on 2+. If S > T, wound on 3+. If S = T, wound on 4+. If S < T, wound on 5+. If S is half T or less, wound on 6+.

Can an unmodified roll of 1 or 6 fail or succeed regardless of modifiers?

Yes. In Warhammer 40k, an unmodified hit or wound roll of 1 is always an automatic failure, and an unmodified roll of 6 is always an automatic success.

Warhammer 40k 10th Edition Wound Roll Chart & Combat Math Guide

Q: Can an unmodified roll of 1 or 6 fail or succeed regardless of modifiers?

Yes. In Warhammer 40k, an unmodified hit or wound roll of 1 is always an automatic failure, and an unmodified roll of 6 is always an automatic success.

Official 10th Edition Strength vs Toughness Wound Matrix

When an attack scores a successful hit, compare the weapon's Strength (S) characteristic against the defending unit's Toughness (T) to determine the required d6 result:

Comparison Rule	Required D6 Roll	Success Probability	Common Battlefield Example
Strength is DOUBLE Toughness (S ≥ 2×T)	2+	83.33% (5 in 6)	Lascannon (S12) shooting Space Marine (T4)
Strength is GREATER than Toughness (S > T)	3+	66.67% (4 in 6)	Heavy Bolter (S5) shooting Imperial Guard (T3)
Strength EQUALS Toughness (S = T)	4+	50.00% (3 in 6)	Bolter (S4) shooting Space Marine (T4)
Strength is LESS than Toughness (S < T)	5+	33.33% (2 in 6)	Lasgun (S3) shooting Space Marine (T4)
Strength is HALF Toughness or less (S ≤ T/2)	6+	16.67% (1 in 6)	Lasgun (S3) shooting Leman Russ Tank (T11)

The Four-Stage Combat Resolution Pipeline

Calculating expected damage in Warhammer 40k requires multiplying success probabilities through four distinct gates:

Stage 1: Hit Roll

Attacks × Ballistic Skill (BS)

Unmodified 6s are Critical Hits. If the weapon has Lethal Hits, these roll directly to the saving throw stage, bypassing the wound roll entirely.

Stage 2: Wound Roll

Strength vs Toughness Table

Successful hits roll against the table above. Weapons with Twin-linked reroll all failed wound rolls, significantly increasing efficiency.

Stage 3: Saving Throw

Armor Save (Sv) + AP Modifier

Armor Penetration (AP) worsens the target's save (e.g. AP -2 on a 3+ save requires a 5+). If the modified save exceeds the unit's Invulnerable Save, the player uses the Invulnerable Save instead.

Stage 4: Damage & FNP

Feel No Pain (FNP) Mitigation

Unsaved wounds deal the weapon's Damage characteristic. If the target has Feel No Pain (e.g. 5+++), roll one d6 for each point of damage inflicted; rolls of 5 or 6 ignore that damage point.

Lethal Hits vs Sustained Hits: Mathematical Efficiency

Two of the most prevalent 10th Edition universal weapon rules interact with critical hit rolls:

Lethal Hits: A Critical Hit (unmodified 6) automatically wounds the target. This rule is extremely high-value against high Toughness monsters and vehicles where you would otherwise wound on 5+ or 6+.
Sustained Hits X: A Critical Hit generates X additional hits. This rule excels against hordes where you already wound on 2+ or 3+, maximizing raw volume.