Iterative Attacks

Gantros · Jan 15, 2009

In general, I like the original idea. I think it's an improvement over the standard iterative attack rules in terms of speed and simplicity. On the other hand, it still has the downsides of reducing the number of attacks a high-level fighter can make, and it still requires 4 rolls (2 attacks + 2 damage) per full attack with all of their attendant modifiers.

Here's an alternative suggestion I came up with. Basically you can choose from two ways to use iterative attacks - against a single opponent, or against multiple opponents.

Single opponent

Make a standard attack. If it misses, no further attacks are possible against that opponent this round. If it hits, roll damage and apply any modifiers or critical effects.

At 6th level or higher, if the attack beats the target AC by 5 or more, total damage is doubled.
At 11th level or higher, if the attack beats the target AC by 10 or more, total damage is tripled.
At 16th level or higher, if the attack beats the target AC by 15 or more, total damage is quadrupled.

Multiple opponents

Make separate attack and damage rolls for each opponent.

At 6th level, you can attack up to two opponents, each at -2 to hit.
At 11th level, you can attack up to three opponents, each at -4 to hit.
At 16th level, you can attack up to four opponents, each at -6 to hit.

Why do it this way? In my experience, iterative attacks are most commonly used to beat on a single opponent, and in this case it seems unnecessary to require multiple rolls with different modifiers. This method lets you get away with one attack roll and one damage roll in all such cases, at the cost of a little bit of extra math. It also gives you the option of hitting multiple opponents as before, which still requires multiple rolls and bonus calculations, but it's simplified by having a single modifier for all attacks. The modifiers were selected to make the 3rd and 4th attacks more meaningful, while keeping the average probabilities of scoring hits relatively unchanged.

You could potentially even combine the single + multiple attack options if desired (e.g. a 16th level fighter attacks two opponents at -2 each, with 2x damage if he beats either AC by 5 or more).

kibbitz · Jan 15, 2009

Gantros said:
In general, I like the original idea. I think it's an improvement over the standard iterative attack rules in terms of speed and simplicity. On the other hand, it still has the downsides of reducing the number of attacks a high-level fighter can make, and it still requires 4 rolls (2 attacks + 2 damage) per full attack with all of their attendant modifiers.

Here's an alternative suggestion I came up with. Basically you can choose from two ways to use iterative attacks - against a single opponent, or against multiple opponents.

---snip---

You could potentially even combine the single + multiple attack options if desired (e.g. a 16th level fighter attacks two opponents at -2 each, with 2x damage if he beats either AC by 5 or more).

Interesting idea, but the need to beat the AC by a certain amount conflicts with the existing mechanic for Power Attack. If you went this route, how would you remodel Power Attack?

Wulf Ratbane · Jan 15, 2009

Gantros, what are the damage expectations on that method?

Gantros · Jan 15, 2009

kibbitz said:
Interesting idea, but the need to beat the AC by a certain amount conflicts with the existing mechanic for Power Attack. If you went this route, how would you remodel Power Attack?

I haven't worked out all the math for it, but I think you should be able to use Power Attack normally. You would just be trading a reduced chance of getting a damage multiplier for an increase in base damage.

Example: Joe the 13th level fighter has +21 to hit vs. AC20 opponent. Normally he'd hit on a 2 or better, do 2x damage on a 4 or better, and 3x damage on a 9 or better. He opts for a +5 power attack, so now he hits on a 4 or better, gets +5 to damage before multipliers, 2x damage on a 9 or better, and 3x damage on a 14 or better.

Wulf Ratbane said:
Gantros, what are the damage expectations on that method?

By my calculations, the single opponent method results in equal to slightly less damage than the RAW. The delta ranges from 0 to -15%, with the biggest difference when using 4 attacks vs. high AC opponents. The variance is due to the fact that iterative attacks can always still hit on a natural 20.

Wulf Ratbane · Jan 15, 2009

Gantros said:
By my calculations, the single opponent method results in equal to slightly less damage than the RAW. The delta ranges from 0 to -15%, with the biggest difference when using 4 attacks vs. high AC opponents. The variance is due to the fact that iterative attacks can always still hit on a natural 20.

I considered a single roll with "levels of success" early on.

I would expect just glancing at it that you'll chop off the top half of the edge cases (high AC) and underperform against the bottom half (low AC). That would be fine as long as there's some compensation in the middle.

EDIT: For the record, I threw out the levels of success model because it requires extra math after the roll to calculate the result.

Gantros · Jan 15, 2009

Actually this method eliminates the low AC problem - in those cases average damage is identical to the RAW, since all of your attacks were almost certain to hit anyway.

The variance only becomes significant when you have >2 attacks and a low probability of scoring a hit on your initial attack, which is a relatively uncommon situation for high level fighters. Essentially, you're only missing out on those occasions where you'd get lucky and roll a natural 20 on one of your extra attacks, which the damage multiplier doesn't account for. Personally I think those occasions, when the fighter manages to deal big damage to a high AC opponent, are rare enough that the speedup in all other situations more than compensates for their loss.

As far as extra math goes, I can't really see a situation where this would require any more of it than your proposal. In the worst case, it requires 1 modified attack roll + 1 AC comparison + 1 modified damage roll + 1 damage multiplier. Your method would require 2 modified attack rolls + 2 AC comparisons + 2 modified damage rolls. The most time consuming part is adding up the modifiers for each roll (plus crit damage, and variable magic weapon effects), so reducing the number of rolls whenever possible is what saves you time and math.

Wulf Ratbane · Jan 15, 2009

Gantros said:
As far as extra math goes, I can't really see a situation where this would require any more of it than your proposal. In the worst case, it requires 1 modified attack roll + 1 AC comparison + 1 modified damage roll + 1 damage multiplier. Your method would require 2 modified attack rolls + 2 AC comparisons + 2 modified damage rolls.

No. Your method requires comparing the attack roll to the AC, then figuring out how much you beat it by, in increments of 5. That ~~is not~~ err, is a non-zero calculation time.

Wulf Ratbane · Jan 16, 2009

I've run the levels of success method and see that it lags behind 0/5/10/15 (4 attacks, RAW) between .09 and .19 at every possible step-- for an average expectation loss of .15.

Definitely not down with that.

whydirt · Jan 16, 2009

What if you made the margins of success +4/+8/+12 instead?

Gantros · Jan 16, 2009

Maybe I'm missing something, but I come up with an average loss of 7.5% across the entire to-hit range with 4 attacks, which is half of what you're getting.

Here's how I calculated:

Let's take a case where you need to roll a 5 or better to hit. By the RAW, that's an 80% hit rate for the 1st attack, 55% for the 2nd, 30% for the 3rd, and 5% for the 4th. Since each attack is roll is independent, expected damage per round is the sum of these, or 170% of the average damage for a single attack.

With level of success, there is a 20% chance for a miss, a 25% chance for normal damage, a 25% chance for 2x damage, a 25% chance for 3x damage, and a 5% chance for 4x damage. Adding this up gives an expected damage identical to that of the RAW.

Using similar calculations for the worst case, when a roll of 16 or higher is required to hit with 4 iterative attacks, the RAW gives an expected damage of 0.4 while level of success gives 0.25.