If Sabine is on a blocking space, can she throw a grenade off onto a non-blocking space?

Why I'd argue no: for this to work you'd have to count spaces from your blocking space to a non-blocking space. Since these spaces are not adjacent you shouldnt be able to count spaces this way.

Why I'd argue yes: Counting spaces says you count the number of movement points a figure would have to use. F.A.Q. v30 says "If a figure or object without mobile occupies a space containing blocking terrain, apply the rules for mobile to that figure or object". From that viewpoint a figure moving off of blocking terrain ignores the terrain, and by extension counting spaces off of blocking terrain should ignore the terrain as well.

1 minute ago, brettpkelly said:

If Sabine is on a blocking space, can she throw a grenade off onto a non-blocking space?

Why I'd argue no: for this to work you'd have to count spaces from your blocking space to a non-blocking space. Since these spaces are not adjacent you shouldnt be able to count spaces this way.  

Why I'd argue yes: Counting spaces says you count the number of movement points a figure would have to use. F.A.Q. v30 says "If a figure or object without mobile occupies a space containing blocking terrain, apply the rules for mobile to that figure or object". From that viewpoint a figure moving off of blocking terrain ignores the terrain, and by extension counting spaces off of blocking terrain should ignore the terrain as well. 

Thanks for posting it here, @brettpkelly -- slight difference in the RRG for "Counting Spaces," which reads:
To determine this number, the player counts the number of movement points it would take for a figure to move from one space to the other. Impassable terrain, figures, and difficult terrain can be moved into and through without costing additional movement point for this measurement. This measurement cannot go through walls, doors, or blocking terrain.

I think we missed earlier that the rule specifically says "This measurement cannot go through walls, doors, or blocking terrain ," which probably stops Sabine's grenade-tracing even IF we apply the "general figure on blocking" rules you mentioned from the Zion's Finest slack-channel thread.

So I think I've talked myself back to the "Sabine can't grenade from the center of the spire" position.

The spaces are not adjacent, but Sabine herself is adjacent to the non-blocking space. We also know that you can draw line of sight and count spaces out of a blocking space (or from it's corner) for attacking. (but see the exception for the center of the Lothal Spire)

You still cannot count spaces through or into a blocking space (only into a figure or object on a blocking space).

Edit: Specifically for the center of the spire - there are diagonal blocking spaces, and you can't count spaces through that intersection.

Good catch, that seems fairly definitive

2 minutes ago, a1bert said:

The spaces are not adjacent, but Sabine herself is adjacent to the non-blocking space.

We also know that you can draw line of sight and count spaces out of a blocking space (or from it's corner) for attacking.

You still cannot count spaces through or into a blocking space (only into a figure or object on a blocking space).

Edit: Specifically for the center of the spire - there are diagonal blocking spaces, and you can't count spaces through that intersection.

What about for a 1x1 blocking space? or from one of the edge spire spaces? You'd still not be able to count spaces out right?

3 minutes ago, brettpkelly said:

What about for a 1x1 blocking space? or from one of the edge spire spaces? You'd still not be able to count spaces out right?

You can attack out of a blocking space without moving, thus you can count spaces for other abilities as well, as far as we agree with the devs it's not limited to attacks. Note that you need an ability where you're counting spaces from the figure, not from the space (because blocking spaces are not adjacent to any other space).

So grenadier reads -> choose a space within 3 spaces. You're saying you count that out from the figure and not from the figure's space?

That's a very subtle distinction.

· If a figure's ability specifies to choose something within a set number of spaces, players count spaces from
the figure using the ability. Likewise, if an ability specifies to choose an adjacent figure, the figure must be
adjacent to the figure using the ability.

If the figure is Large, you choose one space is occupies, so it's not completely consistent (and seems to be only for line of sight), but a Nexu on blocking terrain can certainly attack a figure that is adjacent to it (and thus it is adjacent to the other figure). So, why not count spaces out of the space?

Sure, there's interpretation involved, but if you are asking how it will be ruled... I'm pretty sure.