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Hey guys, this might a very simple thing but I just thought to share some mathematics.

Hull mounted weapons have a 45 degree arc of fire. This translates to 22.5 degrees up or 22.5 degrees down. To quote a friend of mine "how the heck am I supposed to measure 22.5 degrees? I must bring a protractor to a game together wi my tape measure??"

So I've got an easy way to solve those disputes about what the hull mounted weapon can or can't shoot



(Pardon the terrible diagram. Obviously I have no artistic streak.)

Edit: oops! Realized it should be 67.5. Not 62.5. You can see I'm not great at Maths. :p but tan 67.5 is 2.41. I just got the diagram wrong.

So to figure out if the target is too close, we need to know "b"

So the equation would go

b = a(tan 62.5)

Which is

b = 2.41 multiplied by a

Well, that's all the musings for a lazy evening. Hope you guys enjoy this!

Cheers

I don't want to play a game where b = a(tan 62.5) is the easy fix for a gakky rule...

Actually, the diagram helped... wow, so that's how they killed the heldrake. Torrent certainly helps with a target further out, but now it cant touch anything right in front of it either....

Where does it say the arc is evenly distributed up and down? What if I decide the arc is -45 degrees from the x axis?

 azreal13 wrote:
Where does it say the arc is evenly distributed up and down? What if I decide the arc is -45 degrees from the x axis?

Presumably the angle is measured down the barrel. So if the gun is modeled as pointing downward 22.5 degrees, you should be able to shoot everything on the same plane as you, but not higher, and things closer to you then if you had mounted the gun flat to the table.

That's probably a question for YMDC. If it is variable, then someone who is more mathematically inclined might wanna try their hand at this. That's definitely beyond my capabilities.

I find that if you assume the parallel axis to the ground to be the case, it is easier to calculate and speeds up play.

No, you misunderstand.

Take the Heldrake as a very current example.

The model, if assembled officially, points it's gun roughly straight forwards and level. (Along the x axis)

People are assuming that the arc = x +/- 22.5 degrees.

Nothing says that the fire arc cannot be taken as x -45 degrees, meaning it cannot fire above itself at all, but can target 45 degrees down.



As you can see, 45 degrees vertically, no clarification that it has to be split evenly around the x axis.

Hmmm, well that one way to stretch it...Will definitely note.

I actually think its a logical way to rule it to preserve function without contravening RAW.

Makes sense from a fluff perspective (especially for Baledrakes, why would a flyer need an anti infantry weapon that shot up, but that it couldn't bring to bear outside of a ver small sweet spot?) and of you consider some of the sponson weapons (such as LRBT or LR sponsons) their arc isn't evenly distributed either, they can't fire outside of their front 180, despite having a 90 degree travel. I concede that's slightly different as it is hull mount vs sponson, but it does demonstrate the point.

The other major advantage of 45 degree down arcs is ease of play. If you are farther away then I am high, I can shoot you. Closer, and I can’t. Quick, easy, simple and math-free.

 Nevelon wrote:
The other major advantage of 45 degree down arcs is ease of play. If you are farther away then I am high, I can shoot you. Closer, and I can’t. Quick, easy, simple and math-free.

Now how about the player that isn't a Mathhammer and can't position their Heldrake (because of terrain or what not) to get anything to fall in that "sweet spot," which is actually just a fancy way of dismissing the ENORMOUS BLIND SPOTS ALL AROUND THIS MOTHER NOW. And god forbid you've got a Baledrake or something that is using custom rods and such (as a flier) for Apoc games, where something like the Baledrake might have to fly over a titans head? Well then you'll never see the ground. -__-*

Get rid of the 45* arc and give us at least 180. Gives us a maximimum firing range without protractors and such, and we still can't nuke transports we just VS'd. Solves the problem, speeds up the game, makes Chaos happier and GW gets to keep selling Heldrakes.

Too much to ask? Oh right, because this is Chaos we're talking about. -__-

 TheRedWingArmada wrote:

 Nevelon wrote:
The other major advantage of 45 degree down arcs is ease of play. If you are farther away then I am high, I can shoot you. Closer, and I can’t. Quick, easy, simple and math-free.

Now how about the player that isn't a Mathhammer and can't position their Heldrake (because of terrain or what not) to get anything to fall in that "sweet spot," which is actually just a fancy way of dismissing the ENORMOUS BLIND SPOTS ALL AROUND THIS MOTHER NOW. And god forbid you've got a Baledrake or something that is using custom rods and such (as a flier) for Apoc games, where something like the Baledrake might have to fly over a titans head? Well then you'll never see the ground. -__-*

Get rid of the 45* arc and give us at least 180. Gives us a maximimum firing range without protractors and such, and we still can't nuke transports we just VS'd. Solves the problem, speeds up the game, makes Chaos happier and GW gets to keep selling Heldrakes.

Too much to ask? Oh right, because this is Chaos we're talking about. -__-

Unit placement and arc of fire is part of the game. If someone hides where you can’t get an good angle for a shot, that’s them playing smart. Flyers are just a bit trickier then most units.

I do have a lot of sympathy for people who model things to look cool, or have the rules changed on them. Someone who assembled a heldrake when the flamer was 360 didn’t have to worry about where the head was pointed. They do now. If they struck a cool pose where the drake was roaring up at the heavens, can they now only shoot at things above them? RAW, yup.

To be honest, I’d be fine with 180 heldrakes. The 360 was a bit much, but I think hull mounting it is swinging back too far the other way.

 Nevelon wrote:
I do have a lot of sympathy for people who model things to look cool, or have the rules changed on them. Someone who assembled a heldrake when the flamer was 360 didn’t have to worry about where the head was pointed. They do now. If they struck a cool pose where the drake was roaring up at the heavens, can they now only shoot at things above them? RAW, yup.

Funnily enough, Dreadnoughts have had the exact same problem since, well, practically forever. Nobody pays any mind to their weapon fire arcs when assembling or converting them, and there are an awful lot of dreads on the table that technically can't ever actually shoot anything with at least one of their weapons. Players tend to just either ignore the vertical issues in this case, or have just never stopped to consider it and so don't even realise it's a problem because those players who are aware of it wouldn't usually bother pointing it out.

It's only since flyers came along that people suddenly started making an issue of vertical fire arcs, because the issues suddenly became a whole lot more obvious.

If people want to get really picky, just place your helldrake or other flyer on its stand so that it is pointing more towards the ground. That's how a lot of aircraft aim their guns, and while you can't remove a base, there's nothing to say you can't adjust it.
The people I play with are perfectly happy fudging the rules for flyers. No one wants to break out a protractor.
Also, anyone else think it's reasonable to consider the helldrake's neck as part of the baleflamer? The model has clear signs of articulation on its neck, so it seems reasonable to at least start the 45 degree ark from the base of the neck rather then just the nozzle in the mouth.

Sometimes these rules are necessary. I've played before in a game where two hurricane bolters were hovering almost directly over my units and were wiping them out, including the hull mounted multimelta. That was when I wasn't familiar with the rules.

After that episode, I see the fire arc rule being a necessity for reasonable targeting. Still, if taken to extremes, like anything else, would also spoil the fun.