Editing Warhammer 40,000/9th Edition Tactics (section)

====Blast Math====
Every faction has access to weapons with the Blast special rule, which sets the minimum number of shots a ranged weapon can fire to 3 when targeting a unit of 6 or more members, and to the maximum value of its shots when targeting a unit of 11 or more.  Here is the math on the size of the benefit for a variety of numbers of shots; note that a single weapon that shoots 2d6 times will get less benefit than two weapons shooting 1d6 each, and that if your first weapon reduces the target below a size threshold, the second weapon will lose out. Generally speaking, any other mechanics that improve rate of fire, such as re-rolling the dice, stack with Blast but have diminishing returns. 

{| class = "wikitable"
|+ Blast Benefits
! Number of Dice (X) !! Sides !! Average Result !! Result vs 6-10 !! Benefit vs 6-10 !! Result vs 11+ !! Benefit vs 11+
|-
| 1 || 3 || 2 || 3 || 50% || 3 || 50%
|-
| 2 || 3 || 4 || 4.11.. || 2.78% || 6 || 50%
|-
| 3+ || 3 || 2X || 2X || 0% || 3X || 50%
|-
| 1 || 6 || 3.5 || 4 || 14.29% || 6 || 71.43%
|-
| 2 || 6 || 7 || 7.0277.. || 0.40% || 12 || 71.43%
|-
| 3+ || 6 || 3.5X || 3.5X || 0% || 6X || 71.43%
|}

What this means defensively is that if you are worried about being hit by blast weapons, you should not typically field units of size 6-7 (as they will die ''faster'' than units of size 5) or 11-17 (same deal, but compared to 10).