Mass Arrow Fire?

[Azlan]

I don't recall if I read this in a book or on the boards, but I liked the idea. Basically the 50 orcs target an area like 20 x 20. Then each person in that area makes a reflex save or take damage.

But then armor or shields provide no benefit whatsoever against such a rain of arrows. (And in this situation, a shield is especially advantageous.) I think a plodding fighter clad head-to-toe in plate armor would have a much better chance of surviving a rain of arrows than a nimble rogue clad in nothing but leather.

 

[Ankh-Morpork Guard]

But then armor or shields provide no benefit whatsoever against such a rain of arrows. (And in this situation, a shield is especially advantageous.) I think a plodding fighter clad head-to-toe in plate armor would have a much better chance of surviving a rain of arrows than a nimble rogue clad in nothing but leather.

Hmm...well, instead of just rolling for Reflex saves, you could roll an attack bonus for ALL of the Orcs. Just one roll that will count for any that hit. Then, a percent chance based on the number of Orcs. Then just apply the attack bonus against the character that got unlucky with the d% roll.

 

[trentonjoe]

I recall a rule in 2e called Rain of Arrows which may be a useful starting place to modify to 3e.

It took at least 10 archers to begin, and they could then target a 10 x 10 area. Every 10 archers beyond added another 10 x 10 area.
Every archer beyond 10 firing into any 10 x 10 area added +1 damage.
Then all people in the affected area took 2d6 + AC damage.

A few notes:
This was 2e, things didn't need to make sense.
A low AC was a good AC, someone with a -10 (the best) would almost never take any damage.

There was a rule in Axe of the Dwarvish Lords like this. I seem to remember it having a saving throw vs. Breath Weapon. I think Reflex would be most appropraite now.

 

[Azlan]

I adjudicate as if the archers were using indirect fire

Hmm...well, instead of just rolling for Reflex saves, you could roll an attack bonus for ALL of the Orcs. Just one roll that will count for any that hit. Then, a percent chance based on the number of Orcs. Then just apply the attack bonus against the character that got unlucky with the d% roll.

With indirect fire, the archers are not aiming to hit a particular player character, but rather they are aiming to hit the area that the player characters are grouped within. So, whatever rolls are used to resolve this situation, it should not involve each archer's attack bonus with his bow against a character's AC.

So, maybe...

Maybe have each archer using indirect fire roll against a DC, which is determined by the size of the targeted area, and also by the range from the archer to that area.

First, determine the base DC according to the size of the targeted area. Use a base DC of 15 for a 10' x 10' area, which encompass four squares (or 2-4 player characters, in typical D&D formations). Use a base DC of 20 for a 5' x 5' area (that is, for a single square or character). Use a base DC of 10 for a 15' x 15' area, which encompasses 9 squares (or 5-9 characters). Or, if you really need to, use a base DC of 5 for a 20' x 20' area, which encompasses 12 squares (or 10-12 characters).

Next, increase the DC by 2 for each range increment of the archers' bows between themselves and the targeted area.

Now you that you've determined the DC...

Rather than rolling 50 times, once for each archer. do this instead: If the archers all have the same attack bonus, then you can calculate approximately how many of them succeed in landing their arrows in the targeted area. If there are 50 archers, and if each of them has an attack bonus of +5, and if the DC is 17, then each archer needs a 12 or higher on the d20 to succeed, so each archer has a 40% chance for success. So, right off the top, out of 50 archers, only 20 will manage to get their arrows into the area.

Or if that seems like too much calculation for you, then simply roll 50 times, once for each archer. (But, then, if you do that, you may as well roll a normal direct-fire attack for each archer against an individual player character.)

Either way, determine how many archers succeed in landing their arrows in the targeted area, and then divide the number of successes by the number of squares that the area encompasses. That will determine, roughly, how many arrows land in each square.

If, in this situation, the area is 10' x 10', then that area covers four squares, so each square will have 5 incoming arrows. For each player character in an open square, roll 5 attack rolls. The attack bonus for these rolls has nothing to do with the archers who shot the arrows. Rather, the attack bonus for each roll is +1 per incoming arrow. So, with 5 incoming arrows, the attack bonus for each is +5, which is used against the character's AC.

If a player character is using a shield, then against indirect fire he should get twice that shield's AC bonus. A character can also gain an AC bonus from cover against indirect fire, though unless that cover provides overhead protection, it should give only the standard AC bonus. However, no one gains any benefit from any kind of concealment against indirect fire.

Is this process too complicated? Maybe it is. But how else can we quickly and accurately determine a situation that involves 50 archers firing a rain of arrows upon a group of four player characters, with everything being fair and square?

 

[Jeff Wilder]

This is addressed in Complete Warrior.

An earlier poster had it correct: the "target area" for the archers is equal in size and shape to their "formation area." Someone -- I believe the person who has an appropriate feat -- makes an attack roll to place the "target area," and everyone within it then makes a Reflex save with a DC based on a formula I don't recall.

But, as I said, it is in Complete Warrior.

 

[dcollins]

Personally, I really don't like this "area with a Reflex save" adjudication of this scenario that's been handed down from Axe of the Dwarvish Lords (liked that adventure, but Skip played fast-and-loose with a bunch of new rulings like this). Main problem is, the math doesn't come out anything like the numbers would from standard D&D combat.

My preference is either:
(a) following jgsugden's suggestion for a computer program to run the simulation, or
(b) a table (maybe keyed to rolling 2d6 or 3d6 something) that replicates the probability curve of 10 people firing at a time (given certain BABs, ACs, and damage).

Parenthetically, I'm not at all bothered by the "but the attackers aren't aiming at a particular target" issue. At some point each arrow is (at best) flying at a single target, and should be resolved that way, even if the exact target is randomly picked. D&D doesn't use different rules for a single PC firing indescriminately into on onrushing horde -- it shouldn't matter how many people happen to be firing that way.

 

[Rel]

Off the cuff, I'd probably use the Aid Another rules. It's not a perfect fit but (I think) it would achieve the desired result: You almost certainly get hit by one or more arrows; you definately don't get hit by all the arrows. And it takes into account the actual AC of the targets as opposed to a Reflex Save (this lets the guys using shields get hit less).

It would cut down on the total number of rolls and I'd change the numbers of attackers Aiding vs. those Attacking depending on how densely the archers were trying to blanket an area with arrows.

 

[MarauderX]

-- it shouldn't matter how many people happen to be firing that way.

But it does, which is why groups of archers fire together instead of 'at will'. The chance to dodge a group of arrows is much less than just 1 at a time.

I don't like the reflex save idea either, but it may work better than rolling 50 times, randomly determining which arrows were at whom, then giving out damage. The simplier and faster rules always win out for me.

 

[Vaxalon]

I don't like the reflex save idea either, but it may work better than rolling 50 times, randomly determining which arrows were at whom, then giving out damage. The simplier and faster rules always win out for me.

Take groups of twenty orcs.

The number of hits will be 21-AC+AB where AC is the target's total armor class, and the AB is the groups' individual attack bonus. This means that if the AC is 20, and the attack bonus is 2, then there will be three hits. This represents rolling one D20 twenty times, and having it come up with each of the faces once.

If you use groups smaller than twenty (but more than about five) then multiply the total number of hits by a fraction equal to the size of the group divided by twenty.

If you are shooting at a group of people, then apply an equal number of orcs to each member of the group.

 

[dcollins]

I don't like the reflex save idea either, but it may work better than rolling 50 times, randomly determining which arrows were at whom, then giving out damage.

Obviously rolling 50 times at the table is unworkable, we all agree with that. But a brand-new Reflex-save mechanic totally disassociated from the standard D&D rules is inferior to any of the other options above, (a) jgjudsen's computer simulator, (b) my suggested table approach, or (c) vaxalon's method of just taking the average.