New Blast Rules
~Roll BS to hit as usual
~On a miss, the blast weapon has completely missed, no roll to scatter occurs.
~On a hit, the target suffers Xd6 hits, where X is determined by the "size" of the blast.
~~Small blasts are 2d6, Large blasts are 3d6
~~The number of hits is capped at the number of models in the unit. So if you roll 14 hits against a 5 man unit, you inflict only 5 hits, and the rest are wasted

~In addition, place the relevant blast template from the weapon over a model in the target unit within range. Each other unit with 1 or more models touching the template is also hit.
~~These hits are resolved as one dice lower than the original attack. Use the original dice rolled and discard the highest

~An example: A large blast weapon is fired at a unit of 8 Black Templars. There is a unit of 7 Space Wolves in very close proximity to the unit.
~A to-hit roll is made, which is successful.
~3d6 dice are rolled, scoring a 5 and a 4 and a 2 for 11 hits. This results in 8 hits on the Templars
~The blast template is placed on any Black Templar in range, and clips the Space Wolves nearby.
~Those Space Wolves will suffer hits as well. They suffer the two lower dice [4 and 2] for a total of 6 hits.
~Final result is 8 hits on templars, 6 hits on space wolves

 Xerics wrote:
This is a terrible idea. The point of a blast weapon is that even if you miss you can still hit. Your blast rules pretty much invalidate most titan weaponry as well.

Mantic games do it like this and it works just fine, but I feel like your hit numbers are a bit high. A small blast typically covers 3-4 models, large 5-6.

Scoring 1/2 hits on a "miss" might also be worth considering.

 Ustis wrote:
You tried, but haven't really thought it through enough.
With these rules the game would be altered so that for example a deathstrike missile finally launching would do zero damage with its colossal warhead's detonation (which has a blast diameter of hundreds of meters and the warhead is on course directly towards that ultramarine tactical squad) unless you roll a 4+

 rahxephon wrote:
Maybe small blast hit = 2d3, miss = d3
Large blast hit = 2d6, miss = d6

An average of 7 hits for a small blast is generous, I tend to expect 3-4. The reason for 2d3 rather than 1d6 is so you don't have a chance to only get 1 hit which would be rather lame for a hit in my view.

Is a bit messy but for misses could do d3-1 or d6-1or2 so that theres a chance of getting nothing entirely. Don't always want an assured hit I reckon

tgjensen wrote:
You could make it so that on a miss, you deduct a number of hits equal to how much you miss by. So if a Devastator with a missile launcher who would normally inflict D6 hits for a small blast marker rolls a 2 to hit, he misses by one and inflicts D6-1 hits. If he'd rolled a 1 he'd do D6-2 hits.
You could deduct the number of hits for each dice in case of large blast markers, so there's always a chance of missing completely. A Vindicator rolling a 1 to hit would then do 2D6-4 hits, and an Ork Battlewagon with a Killkannon that rolled a 1 would do 2D6-8 hits.

 AlmightyWalrus wrote:
So I shoot a Deathstrike Missile at one squad and the dude in another unit stood right next to them can't even take damage from the nuclear missile I just hit his mates with?

I don't much care for apoc blast weapons, but by all means give them some other buff. E.g. all units within 3" of the target unit take d6 hits.

I just thought that if blasts from grenades and the like were introduced like this that infantry would be taking too much of a devastating nerf to their durability and may become even more of a liability in certain armies.