Scattering Blast Templates & Lower Levels: House-Rule Workshop

[Commissariat]

Hello Underhivers!

As the book appears to have no rules for scattering off of edges, potentially allowing RAW to let you scatter a grenade onto someone 20" below... I'm trying to devise a house rule for it beyond simply poofing the grenade into nothing once it falls off a one inch cliff.

Spoiler: Standard Scenario: Scattering Down ONE "Level"

Following the diagram below for reference, a blast can scatter (and hit models on the next floor down) if the distance to the edge and then down to the surface below is equal to or less than the scatter distance rolled.
If the distance is short enough, the blast will scatter full distance on the horizontal plane until it hits the edge. When it passes the edge, the remaining scatter distance is halved as it continues to scatter on the horizontal plane. All models on that level are hit by the blast template.

Spoiler: Tricky Scenario: Multiple Levels

A scenario like scattering from C to B is trickier if you are considering being able to hit A.

Idea: If A were a low enough to be wholly under the base of B, it is an obvious miss. If A were partially or fully level with B's base, then I'd say it could be possible to hit A with a blast template at B's Level.

 

[Jacob Dryearth]

Why does the scatter distance decrease if it falls further? Wouldn't it continue its parabolic trajectory and thus scatter even further horizontally from the intended target as it drops to the lower level?

Edit : would it be simpler to say that for every inch of horizontal movement past the target plane, it drops one inch?

 

[Thorgor]

I suppose it depends whether scattering is meant as a way to represent the grenade bouncing around or simply rolling on the floor.
What about a grenade that should explode in mid-air? Does it simply disappear, or does it explode when it touches the floor? (or does it actually explode in mid-air?)

As for the second scenario, I always considered grenades AoE to actually be a sphere and not a flat disc (or cylinder). As long as the fighter is within 3" or 5" from the center and there is no obstacle, they should be hit imo.

 

[Fold]

It could be any of those things, or a plain old missed throw, or one that has ricocheted off of some obstacle on the way. I do like the “it travels 1” down for each 1” it leaves the target plane” suggestion, combined with making the grenade a spherical blast.

 

[Commissariat]

Since we are playing in a medium that makes it hard to measure in "mid-air" for that sort of scattering and since it has been smartly pointed out that my initial idea is not that accurate of trajectory for most scattering-scenario-abstractions, a new plan:

Measure normally to the edge where the cliff starts, then measure half the distance vertically along the cliff-face, and spend any remaining measurement continuing the scatter horizontally.

So, scattering off of a 3x3" box and scattering 5" starting at the edge would be: 1.5" down and then 3.5" from the bottom of the cliff.

Does this, as well as making the blast template a sphere, seem close to the optimal idea that @Fold picked out of the thread so far?

 

[Thorgor]

Measure normally to the edge where the cliff starts, then measure half the distance vertically along the cliff-face, and spend any remaining measurement continuing the scatter horizontally.

I'm confused. Isn't it the same as the image from your first scenario? Same rules as a fighter walking in a straight line and using ladders to move vertically.

 

[Commissariat]

The 1st one halves the distance pass the edge horizontally, looks similar but in practice has a different effect.

 

[Fold]

What are you trying to achieve by basing the total scatter distance partly on the height of the building you’re scattering off? This doesn’t make much sense to me.

 

[Stoof]

When grenades scatter, we scatter them the full distance horizontally (walls etc permitting). If they fall they fall all the way to the ground.

If you don't fancy that, we had an old house rule that we've only every actually needed once or twice in 20 odd years: if a grenade falls more than 10" vertically it explodes in the air at the 10" mark, the blast being spherical.

I can't remember why we came to that conclusion other than 10" feeling "about right" for a grenade to explode at automatically after it's bounced/rolled around a bit whilst ticking down from 3 seconds.

 

[Fold]

I still think a vertical distance equal to the horizontal makes more sense than an arbitrary value, whether set as in stoofs 10” rule or based on half the height of the building.

 

[p0dde]

@Commissariat, interesting rule. Making 'realistic' scatter seems like a challenge though. After having played with the NCE scatter, I sort of enjoy the playfulness of the extreme scattering in N17.

EDIT: re-reading the rules, I think that the scatter rule takes care of it pretty nicely.

"roll a Scatter dice and a D6. The marker moves in the direction shows on the Scatter dice (using the small arrow if the hit symbol is rolled) a number of inches equal to the number on the D6. The marker stops if the central hole comes into contact with a wall or closed door. "​

When scattering D6 inches, it is only when scattering upwards that you get into some weird cases. Like a thrown hand grenade scattering 9-12" to the roof of a building. But in that case it will just be stopped by the wall of the building and end there. On the other hand when a grenade scatters downward, it will, in many cases, not hit a wall, and end up falling down to a lower level.

Of cause we can get into trouble with, what constitutes a wall? In @Commissariat example, the 1" height difference is not enough to be called a wall, and the marker will not be stopped, but just continue the D6 inches, but I would say that 2" should be enough to stop it?

And it also makes blast weapons a lot more powerful than what we are used to. When shooting into a small building with only 1 or 2 doors, you will be pretty sure that marker will stay inside the building, when it scatters.

 

[Commissariat]

@p0dde There are no rules for limiting scatter distance, grenades go wild.

@Fold
This house rule is mostly for use in Tabletop Simulator, which one of the downsides is making it hard to measure things in the "air" because the measuring tool measures between surfaces. Unless we manipulated an in-game ruler stick, which is too tedious for a fluid game, we are looking for an alternative.

What are you saying about about "half the height of the building"?

We are trying to avoid outright dissipating blast templates while also having a comfortable scattering method. It could very well end up being something like the 10" plan.

 

[Thorgor]

re-reading the rules, I think that the scatter rule takes care of it pretty nicely

They are not supposed to take care of it. The rules for scattering are only found in Underhive and as a result totally ignore the third dimension. RAW would make the grenade scatter in a horizontal line, ignoring gravity.

We don't know how grenades falling off ledges is supposed to work. Gang War 1 gives us a few rules we could try to adapt (a ganger falling is instantaneous and doesn't "eat" movement, but of course a grenade isn't gonna take any Initiative check and falling still take time IRL. The grenade falling at double (or triple) movement speed in a straight vertical line looks like a good compromise.)

 

[p0dde]

They are not supposed to take care of it. The rules for scattering are only found in Underhive and as a result totally ignore the third dimension. RAW would make the grenade scatter in a horizontal line, ignoring gravity.

My point is that 2D rules translates well to 3D. You need a definition for what constitutes a wall, but then it pretty much works. gravity-wise it will never scatter upwards, but only downwards. (Technically, it could scatter up stairs and slopes, which is a bit weird, but it would need a pretty perfect scatter...)

 

[Fold]

@Fold
This house rule is mostly for use in Tabletop Simulator, which one of the downsides is making it hard to measure things in the "air" because the measuring tool measures between surfaces. Unless we manipulated an in-game ruler stick, which is too tedious for a fluid game, we are looking for an alternative.

What are you saying about about "half the height of the building"?.

That’s what I understood you to mean when you said “measure half the distance down the cliff face”. Perhaps you meant half the distance remaining in the scatter after measuring to the edge of the platform the scatter started from?

 

[Thorgor]

That’s what I understood you to mean when you said “measure half the distance down the cliff face”. Perhaps you meant half the distance remaining in the scatter after measuring to the edge of the platform the scatter started from?

What I understand is that the grenade falls at "double speed".
For example, if it must scatter 6" and starts at 1" of a 3" high cliff, it will first travel 1" horizontally, then fall 3" vertically (counted as 1.5") and then travel horizontally for the remaining 3.5".

 

[Commissariat]

Oh I thought you were coming up with another idea, my bad.