Wolf Claw

Wolf Claws are an excellent weapon, not only do they look good but they're good in game too. Just like a standard Lightning Claw they count as a power weapon and you only get an attack bonus if you have two, but they have the bonus that you can choose to re-roll your to hit rolls or your to wound ones. You have to decide before each round of combat which you're going to re-roll which leaves the question, 'when should I re-roll misses and when should I re-roll failed wounds'?

So, the guys who can take a Wolf Claw have Weapon Skill of 4 (Wolf Guard), 5 (Wolf Guard Battle Leader, Canis) or 6 (Wolf Lord) and have a standard strength of 4 unless on a Thunderwolf in which case it is 5.

So, let's look at opponent's WS less than ours and toughness is at least 2 less than our strength:

P(Cause a Wound) = P(Hit) x P(wound)
= 2/3 x 5/6
= 5/9

Re-rolling hits = 8/9 x 5/6 = 20/27

Re-rolling wounds = 2/3 x 35/36 =35/54

Re-rolling hits is better

Now, let's look at opponent's WS same or higher than ours and toughness is at least 2 less than our strength:

P(Cause a Wound) = P(Hit) x P(Wound)
= 1/2 x 5/6
= 5/12

Re-rolling hits = 3/4 x 5/6 = 15/24

Re-rolling wounds = 1/2 x 35/36 = 35/72

Re-rolling hits is better

Opponent's WS is less and toughness is 1 less than our strength:

P(Cause a Wound) = P(Hit) x P(Wound)
= 2/3 x 2/3
= 4/9

Re-rolling hits = 8/9 x 2/3 = 16/27

Re-rolling wounds = 2/3 x 8/9 = 16/27

Exactly the same

Opponent's WS is the same or higher and toughness is 1 less than our strength:

P(Cause a Wound) = P(Hit) x P(Wound)
= 1/2 x 2/3
= 1/3

Re-rolling hits = 3/4 x 2/3 = 1/2

Re-rolling wounds = 1/2 x 8/9 = 4/9

Re-rolling hits is better

Opponent's WS is less and toughness is the same as our strength:

P(Cause a Wound) = P(Hit) x P(Wound)
= 2/3 x 1/2
= 1/3

Re-rolling hits = 8/9 x 1/2 = 4/9

Re-rolling wounds = 2/3 x 3/4 = 1/2

Re-rolling wounds is better

Opponent's WS is the same or higher and toughness is the same as our strength:

P(Cause a Wound) = P(Hit) x P(Wound)
= 1/2 x 1/2
= 1/4

Re-rolling hits = 3/4 x 1/2 = 3/8

Re-rolling wounds = 1/2 x 3/4 = 3/8

Exactly the same

Opponent's WS is less and toughness is 1 higher than our strength

P(Cause a Wound) = P(Hit) x P(Wound)
= 2/3 x 1/3
= 2/9

Re-rolling hits = 8/9 x 1/3 = 8/27

Re-rolling wounds = 2/3 x 5/9 = 10/27

Re-rolling wounds is better

Opponent's WS is the same or higher and toughness is 1 higher than our strength:

P(Cause a Wound) = P(Hit) x P(Wound)
= 1/2 x 1/3
= 1/6

Re-rolling hits = 3/4 x 1/3 = 1/4

Re-rolling wounds = 1/2 x 5/9 = 5/18

Re-rolling wounds is better

Opponent's WS is less and toughness is 2 or 3 higher than our strength:

P(Cause a Wound) = P(Hit) x P(Wound)
= 2/3 x 1/6
= 1/9

Re-rolling hits = 8/9 x 1/6 = 4/27

Re-rolling wounds = 2/3 x 11/36
= 11/54

Re-rolling wounds is better

Opponent's WS is the same or higher and toughness is 2 or 3 higher than our strength:

P(Cause a Wound) = P(Hit) x P(Wound)
= 1/2 x 1/6
= 1/12

Re-rolling hits = 3/4 x 1/6 = 1/8

Re-rolling wounds = 1/2 x 11/36 = 11/72

Re-rolling wounds is better

Phew! That's a lot of numbers! It should be noted that I've not included WS 5 vs WS 9 or 10 and I've not included any Space Wolf bonuses such as Wolf Tooth Necklace or Saga of the Beastslayer.

So, what does it all mean? Well, basically if you need to roll a lower number to hit than to wound re-roll our wounds and if you need a lower number to wound than to hit then re-roll your hits. If it's the same, for example if you're up against Space Marines and need a 4 followed by a 4, I'd always be tempted to re-roll hits and you want to maximise the number of dice you're rolling when you come to wounds. However I am notoriously bad at rolling my to hit dice.