Blast Weapons with [BLAST] in their profile are known as Blast weapons, and they make a random number of attacks. Each time you determine how many attacks are made with a Blast weapon, add 1 to the result for every five models that were in the target unit when you selected it as the target (rounding down). Blast weapons can never be used to make attacks against a unit that is within Engagement Range of one or more units from the attacking model’s army (including its own unit).
Rapid Fire Weapons with [RAPID FIRE X] in their profile are known as Rapid Fire weapons. Each time such a weapon targets a unit within half that weapon’s range, the Attacks characteristic of that weapon is increased by the amount denoted by ‘x’.