Grenades are a lot of fun in Deadzone, but the way they work in 3D is not very well explained in the Alpha. So, here I am to expand on that.
Firstly, a general note on 3D LOS. When attacking an square that is on a higher level with area fire you count as being able to see that square if you can see the edge or the corner of the floor. Assuming, of course, that there isn’t a solid wall blocking that side.
In terms of grenades, the Alpha already explains how to resolve explosions in 2D. Let’s add the third dimension.
This diagram is a side-on view of a grenade exploding on top of a single level block (B). Yes, it’s not a pretty sight, but them’s the dangers of dealing with Alphas 😉
The effect it has on adjacent squares (really cubes as we’re talking 3D) is as follows:
A: No effect. Grenades explode sideways and up, but not down. As the grenade will be lying on the floor, the blast will be blocked from damaging either square marked A.
B: No effect. If there was a hole in this square then there should be a chance of it falling through the hole (for the Alpha ignore this chance). If it does not then it can be assumed to be too far away for the blast to go down in much the same manner squares A are protected.
C: These adjacent squares on the same level as the explosion take the normal effect from the blast as adjacent squares.
D: If we assume that these squares are open on the side facing the explosion and that they are one level higher then they too are adjacent and subject to the normal rule for blast effecting adjacent squares. Remember though that as any potential targets will be higher than the source of the attack they will count as being in cover and so will get an extra dice.
Quirkworthy 
Makes sense. Which is the goal, one would imagine.
I’m not sure that I understand: you write that the grenade explode on top of the B square, but the explosion is clearly centered on the square on top of B in both the picture and the rest of the description, what did I miss ?
Square B is a building, you are viewing it side on, the grenade has exploded on top of B i.e. on the flat roof of the building
Exactly so.
I have a question. If the grenade is aimed at the top of B, a single block, and scatters one square, where does it end? C is directly adjacent to B so the grenade should explode there. But C is an empty square and logically the grenade ought to fall down further to the ground, ending in A.
Follow the logic 🙂
If the grenade scatters into an empty square then it will fall to the ground on the level below. In this case, A as you said.
But it could have blow up in the air ? I think there cases where there is 3d scattering, going one square higher or lower if possible. A simple way to do it is first normal scatter for 2d with the 1d8, and with another 1d8 :
1d8 = {5,7} -> original level
1d8 = {1,3,6} -> lower level ( if possible, if not original level)
1d8 = {2,4,8} -> higher level ( if possible, if not original level)
So in this way you just need 2d8 in order to have a 3d scatter. I know the original level doesn’t have sometimes the same probability that the other two but also some times it has a lot more when higher or lower are not possible, so IMHO this compensate that imbalance.
I like it Jake, I take it from reading how D works that were the target square inside a building, anyone on, eg, a gantry or walkway running around at D would get hit too? Really damaging to lob into buildings- will models be able to throw through windows, given they wont be able to se corner/edge of floor?
(Also, you’ve probably thought of this, but a 3D, isometric diagram of this would be ideal in the finished book so make it clear as possible!)
You should be able to throw through windows – it makes sense – which does imply the LOS rules need tweaking.
I’m thinking of using photo diagrams if possible in the final version.
That would be cool, I was thinking about the LOS through window- it would work the same essentially, only rather than see the corner/edge of tile you’re aiming at, the one above or opposite would do it? (The way people in computer games ‘bounce’ grenades off opposite walls).
Now that the grenade rules are out, there’s still an unsolved issue at hand: do they work against zombies? 😉
Depends on which zombies…
…and which grenades…
How high up should you be able to throw a grenade? Have you given that any thought?
Also, sometimes you might be able to see a place, but logically not be able to throw a grenade there. Will you leave such situations alone for simplicity’s sake? I imagine players, knowing their own terrain, could set certain guidelines themselves. I could see myself doing so, anyways.