How to Model: Splash Damage

[Xotl]

I'm looking to recreate spells from D&D that have the effect of "if it hits it does full damage, and if it misses it still does half (or quarter, whatever) damage".  But of course, this has application outside of Fantasy.

 

To some degree this could be special effects, by stating that since you're doing damage you really didn't miss, did you?  But these effects are usually predicated on an attack roll and yes, the effect really does occur on a failed to-hit roll.

 

The reduced damage from the miss (the splash effect) is also tricky.  I don't want to do just do area effect explosion because the attack may not be an area effect attack.

 

I can always make a custom advantage.  I just want to make sure I didn't miss anything already in the rules first.

[Hugh Neilson]

What about putting AoE on half of the attack (or whatever portion you want to apply on a miss - "half" typically is nothing once defenses are applied)?

 

This could be AoE Accurate (half the attack hits a DCV of 3, but you get full damage only if you hit with full attack), AoE Radius (the target takes full damage on a hit, half damage on a miss, and everyone around him takes half damage regardless) or AoE Explosion (the target takes full damage on a hit, half damage on a miss, and everyone around him takes damage that declines the further away they are).

 

A poor enough roll to hit and the center of the area is mistargeted, but that comes from D&D not allowing AoE to miss at all.

[bigdamnhero]

Off the top of my head, I'd say either:

 

1) Build half the damage with AOE 1m Radius Selective so it only affects one target, or

2) Build half the damage with enough levels of +OCV that it's functionally guaranteed to hit.

 

In either case, the second half of the damage is Linked, maybe with an additional Limitation for "Only adds to damage if attack hits by +X" or something.

[Christopher R Taylor]

Perhaps an attack with a linked AE, the link only going off if the attack misses.

[IndianaJoe3]

This might be a case where trying to do a literal translation of the effect doesn't work (because d20 and Hero use different armor models). Can you give a specific example of something you are trying to recreate?

[Chris Goodwin]

In D&D 5e at least, the vast majority of the ones you roll to hit for are all or nothing and don't take saving throws.  Almost all of the ones that auto-hit let the target save for half damage, if not less.  And Hero already has avoidance type rolls -- Block, Dive For Cover, Roll With The Blow.  There are also lots of effects that increase a target's DCV to avoid the damage in the first place.  And it's not too much of a stretch to give an attack a Limitation to the effect that the target takes half damage if they can make a particular Characteristic Roll.  That doesn't do away with the need to make an Attack Roll to hit, though.

 

I agree with the general guideline to not try to simulate another game's mechanics.  Give your Power the half damage on a successful Characteristic Roll because that's how the Power works, not because that's how the original system does it.

[Xotl]

Make a ranged spell attack against the target. On a hit, the target takes 4d4 acid damage immediately and 2d4 acid damage at the end of its next turn. On a miss, the arrow splashes the target with acid for half as much of the initial damage and no damage at the end of its next turn.

 

Acid Arrow: roll to hit, and if you hit you do do damage now + half damage later.  If you miss, you do half damage now.

 

It's interesting, as since I've posted I've had lots of opportunity to think about this one spell but also conversion approaches in general.  I forgot that just because it's one effect in D&D it can be two or more in Hero, so bigdamnhero's/Christopher Taylor's solution works well.  At the same time, I realized that I'm not really interesting in recreating all the basic effects Hero can already do, but just the weird D&D spells that do atypical things you probably wouldn't think of yourself.  In other words, why convert Alter Self (Shape Change) or Aid (Aid) when there's something like Alarm or Animal Shapes to think about?

 

It's also made me realize just how boring most damage spells are in general: "ah, but this one is 4D6 damage, not 3D6, and the SFX are different".  But I do miss the abitrary ability to just say "this works" and call it a day that D&D has, because my god some of these power builds are ridiculously long.

[Hugh Neilson]

Let's assume the Acid Arrow is to be a 2d6 RKA which, if it hits, does 1d6 KA again a phase later and, if it misses, still does 1d6 KA on the phase of the attack.

 

2d6 RKA (30 AP) is pretty easy.

 

Tack on AoE 1 hex Accurate on 1d6. That costs 15 x 1/2 = 7 AP. If the target's DCV is missed but DCV 3 is hit, the target takes 1d6 HKA. In fact, let's make it 4 meter radius, Accurate, for the same cost - if you miss the hex by a bit, the target is still hit. To further reduce, or eliminate, the potential that "half damage" misses, make the radius bigger.

 

Add on Damage over Time (+1), 2 damage increments (+1/4), Damage occurs every three segments (+1) on 1d6, which costs 15 x 2.25 = 34 AP, which works only if the initial attack hits (perhaps we call that -1/2 limitation - depends how common hits and misses are in game - which I will not math out here as most spells have other limitations) to the 1d6 that does not get AoE.

 

The problem is not that the construct can't be done, but that the DoT aspect is very expensive for the thrill of getting a second attack. So how else could be build that?

 

We could instead apply Constant (+1/2), Uncontrolled (+1/2)to the 1d6 of the RKA which is not AoE for 15 points. If you hit, that 1d6 keeps going. It could either be limited to only one extra phase, or the caster could have the added flexibility of adding END for as many, or as few, extra attacks as he desires. That seems like a pretty cool spell.

 

It could be a Trigger that goes off one phase after the initial attack hits, but that will require a second roll to hit, so it likely needs that AoE again, it activates with no time cost and takes zero phases to reset (added to the spell itself). That's a +3/4 advantage, almost as costly as Constant Uncontrolled and much less versatile. It also feels kludgier.

 

RESULT

 

So that's a 2d6 RKA (30 AP), 1d6 having AoE 4 meter radius, Accurate, (+7 AP) and 1d6 having Constant, Uncontrolled (+15 AP) = 52 AP. You could have purchased a 3d6+1 RKA for 2 points less, but this one is pretty much guaranteed to inflict at least a 1d6 RKA on any target, and can last for an extended period if you pump up the END on that Uncontrolled aspect.

 

As with most Hero things, there are a variety of ways to simulate the effect, each with minor advantages and drawbacks. I like the Constant Uncontrolled variant as it provides the caster with more tactical choice, and has what seems a reasonable cost.

[Hugh Neilson]

BTW, I definitely agree with the sentiment that, if the goal is to use Hero to identically recreate D&D, one may as well play D&D.

[Christopher R Taylor]

Here's how I modeled the "always hits unless they resist" mechanic in Hero:

 

 

AVAD Saving Throw: Players may build powers with an alternate form of AVAD which, instead of being blocked by a special defense or circumstance, is reduced or eliminated by a skill or characteristic roll.

• If this roll is one that all characters have at a normal level (such as a characteristic roll or perception roll), then the advantage is +1/2.
• If the roll is an unusual one or one that characters normally only have as a familiarity (such as stealth or a magic skill roll), then the advantage is is +3/4.
• If the roll only halves the effect of the power rather than ignoring it, the advantage is +1/2.
• If the roll is modified by -1/10 active points of the power it is +1/4 more of an advantage.

 

I haven't had a chance to playtest this very much but it seems to function pretty well and gives the results you have in mind.

 

People should remember the idea of "magical resistance" isn't limited to D&D, its more or less standard to fantasy gaming on all sorts of platforms.  It even shows up in quasi-magical settings such as psionics or "the force" in Star Wars.

[Hugh Neilson]

People should remember the idea of "magical resistance" isn't limited to D&D, its more or less standard to fantasy gaming on all sorts of platforms.  It even shows up in quasi-magical settings such as psionics or "the force" in Star Wars.

You mean like having a mental DCV, or an EGO roll to shake off the effects of mental powers, or defenses?

 

A roll for half (or no, or reduced) damage is only one of many ways to simulate resistance to a given effect.

[Christopher R Taylor]

A roll for half (or no, or reduced) damage is only one of many ways to simulate resistance to a given effect. 

 

 

Sure, its one of the tools in the box.  I just wanted to point out that people who keep saying this is D&D isn't necessarily.

[dsatow]

I don't think it matters why they want to introduce the mechanic, as its their game, though I kind of agree with Chris Goodwin in that Hero has mechanics for this.  Dropping an attack by half, unless it goes against a specialty defense (non PD/ED) will usually make the attack become ineffectual.  But to proceed.

 

The simplest way is to put a limitation on an area of effect that says if you make a X roll you take half damage.  I'd give it a -1 limitation since half damage is pretty limiting but not always successful.  

 

Example: in a 12DC game a 10d6 AoE radius 4m blast with the limitation would do 35 STUN to those who fail but 17 STUN to those who make the roll. Most 12DC games, PC and Villains run around from 20-30 defenses, so it effectively gives the targets a free dive for cover roll.

 

The next way is to partially limit half the attack with a requires a roll (-1) but instead of activating, the roll would deactivate.  I'd say treat it at the 11- to start with and then determine how much your average characteristic roll is above that.  If your roll average roll is 14-, then the requires a roll should be valued for a roll at 8-.

 

Finally, you can add extra damage in the form of an NND of the same area.  The defense of the NND is making the roll by so much.  Thus if you don't make the roll by X amount, you effectively take Xd6 extra stun.

[Hugh Neilson]

Here's how I modeled the "always hits unless they resist" mechanic in Hero:

 

AVAD Saving Throw: Players may build powers with an alternate form of AVAD which, instead of being blocked by a special defense or circumstance, is reduced or eliminated by a skill or characteristic roll.

•If this roll is one that all characters have at a normal level (such as a characteristic roll or perception roll), then the advantage is +1/2.

•If the roll is an unusual one or one that characters normally only have as a familiarity (such as stealth or a magic skill roll), then the advantage is is +3/4.

•If the roll only halves the effect of the power rather than ignoring it, the advantage is +1/2.

•If the roll is modified by -1/10 active points of the power it is +1/4 more of an advantage.

Let's consider this from the vantage point of a limitation on the attack power. It doesn't have to be an "NND" type construct.

 

Analogizing the mechanic to one that already exists is my general preference - we have set values for those already. Here, I think the best basis is Requires a Roll.

 

Normally, a required roll is either a fixed roll (not the case here - it will vary with the target) or a skill roll modified by -1/X AP.

 

If all characters have the roll at a normal level, it seems resistance on 11- will be common, and a lot of targets will have a better roll. Let's call that a 12- on average. The odds of a 12- roll failing are the same as a 9- roll succeeding, so that implies a limitation of -1 1/2 (base roll of 11- is -1/2, a further -1/2 for rolling with every use and a further -1/2 for reducing the activation roll to 9-).

 

If the roll is an unusual one or one that characters normally only have as a familiarity, then the target will typically succeed on an 8-, but may have a better roll, so maybe we call that 9-. Odds of failure being 9- is equivalent to activating on a 12-, so that's -3/4 (base roll of 11- is -1/2, a further -1/2 for rolling with every use reduced by -1/4 for improving the activation roll to 12-)

 

Now, a skill-based roll reduced by -1 per 10 AP is normally also a -1 limitation, but the character taking the limitation will normally have a pretty decent roll on that skill. Here, the targets likely won't. However, here we know the AP of the specific power, so we can just adjust the activation roll to compensate. If the power fails based on a normal skill/PER roll succeeding, and we set that at a 9- activation roll, then a -4 (1/10 of 40 AP) penalty to the target's roll is an activation roll 4 points higher - so base the limitation on a 13- activation roll instead of a 9- activation roll. That reduces it to a -3/4 limitation.

 

If the roll only halves the effects, then only half of the power is limited. Only apply the limitation to half of the power.

[Christopher R Taylor]

The reason I built it as an AVAD variant is so that it also ignores defenses, giving an alternate defense structure of a roll to protect rather than set defenses.  If the defenses are still applicable then yeah it would be a limitation: an additional level of protection applied would weaken the power.

[Hugh Neilson]

What if I want it to inflict BOD damage? Presumably, that costs an extra +1, although your notes don't state that specifically.

 

What if the attack would have acted against a less common defense to begin with? Maybe I wanted a Killing Attack, or a Ray of Enfeeblement?

 

Let's see how the pricing plays out if I start with normal damage:

 

So if I just want to do STUN damage, your model would, I believe, set 6d6 against a CON roll at 45 AP.

 

Mine would set the AP considerably higher, 6d6 vs appropriate Life Support, all or nothing, would be 60 AP. After the -1 1/2 limitation, that's 24 real points. I can tack on half END for 67 AP, 27 real points. That seems like your construct is overpriced for its value.

 

If I want BOD as well, is that an extra +1, so 75 AP and RP, in your model?

 

In mine, it would be, so 6d6 is now 90 AP, 36 real points - so mine does BOD at less RP cost than your non-BOD power.

 

I'm thinking that your model sets my failure risk too high for the points saved, so I'd avoid it. I'll admit, however, that I may be biased due to my strong preference for using existing mechanics rather than setting an arbitrary new advantage or limitation cost, where practical.

[Hugh Neilson]

Tack on AoE 1 hex Accurate on 1d6. That costs 15 x 1/2 = 7 AP. If the target's DCV is missed but DCV 3 is hit, the target takes 1d6 HKA. In fact, let's make it 4 meter radius, Accurate, for the same cost - if you miss the hex by a bit, the target is still hit. To further reduce, or eliminate, the potential that "half damage" misses, make the radius bigger.

Thanks for getting the rulings question from Steve, Lucius. That's one I'll be ignoring in my games, though, since it results in the extra cost of a larger area providing no real benefit to the character. I suppose it might allow you to target an adjacent hex, so you only have to hit OCV 0 (maybe not - the RAW on Accurate says "must hit DCV "), but I think that making the area bigger should provide an advantage. I would, however, think it is reasonable to add +1/4 for the increase from "1 meter/target" to up to a 4 meter radius.

 

One could argue the advantage is removing the potential of hitting undesired targets in the area, but Selective does that as well, for a +1/4 advantage.

 

Effectively, that makes 4 meter radius (+1/4), Accurate (+1/4), Selective (+1/4) a +3/4 advantage. That's the same result we get if increasing Accurate from "single target - DCV 3 misses his space" to "single target, as long as he is in the 4 meter radius after the scatter if you miss" an extra +1/4.

 

Maybe I am biased - I suggested when 6e was in progress that nonselective should be the default for AoE, with the ability to bypass the normal To Hit roll, and the ability to pick and choose targets within an area, both being separated, and Accurate being an advantage outside AoE entirely.

 

If we priced Accurate at +1/2 as an independent Advantage (use DCV 3 rather than target's actual DCV), that would simulate the present model pretty well. With an AoE, that would mean the single roll to hit DCV 3 targets the area and everyone in it.

 

Pre 6e, I've used "AoE, Selective" plus "AoE, 1 Hex Accurate" to allow the character to strike each desired target in the area with a successful roll to hit DCV 3, and that worked out OK. A lot less fiddly than "AoE any area" and designing a configuration that captures the desired targets while avoiding the others. That was in a Supers context, where "hit DCV 3" and "hit automatically" were pretty much the same thing 215 times out of 216 (ie OCV 9+ was pretty much universal, so you only missed DCV 3 on an 18 anyway).

[Christopher R Taylor]

What if I want it to inflict BOD damage? Presumably, that costs an extra +1, although your notes don't state that specifically.

 

Yeah that's the stripped down model, since its built around AVAD it follows all the same rules.

 

What if the attack would have acted against a less common defense to begin with? Maybe I wanted a Killing Attack, or a Ray of Enfeeblement?

 

The concept is built around the principle laid out in AVAD: the more the shift from an ordinary defense, the greater the advantage.  Since this is not based on any ordinary defense, but is instead adding an alternate defense, I just assigned it a single shift for the base, and a greater shift for the more effective the attack.

 

The roll puts the defense in the hands of the target and their skill, which is variable.  One person could have a 18- CON roll while the other has a 10- (very sickly).  So you shoot for averages, and the base 11- give a roughly 50/50 chance of making the roll.  But since everyone has a constitution roll (except, presumably, targets that wouldn't be affected by an attack targeting CON rolls), the defense is incredibly common.  So the advantage shouldn't be worth a lot.  however, since it is ignoring defenses entirely, its worth a fair amount of advantage.

 

That's the concept, anyway.  Again, I haven't had a chance to playtest this the way I'd want to, so I can't really say out it works out in terms of balance.  

 

For example, I have a variant of ACV which uses a skill/other roll to resist as well (in other words, it doesn't target a combat value, it just always hits, unless they make a roll).  And a "Seeking" advantage concept that is a CV version of DOT - that is, it keeps trying to hit over and over instead of keeping doing damage over and over.

 

For me this kind of thing is like Advanced Player Guide concepts filling little gaps in the rules or difficult to model concepts with an easier and straight forward build.  But they need extensive play to polish up.

[Hugh Neilson]

The roll puts the defense in the hands of the target and their skill, which is variable.  One person could have a 18- CON roll while the other has a 10- (very sickly).  So you shoot for averages, and the base 11- give a roughly 50/50 chance of making the roll.  But since everyone has a constitution roll (except, presumably, targets that wouldn't be affected by an attack targeting CON rolls), the defense is incredibly common.  So the advantage shouldn't be worth a lot.  however, since it is ignoring defenses entirely, its worth a fair amount of advantage.

A roll of 11- provides a 62.5% chance of success, not a 50/50 chance of success. 10- (or 11+) is 50/50. I also expect most adversaries (and most PC's) will have a 13+ CON - I could argue the basis should be an 18+ expectation, but I think that is too high for a Heroic Fantasy game average. Every enemy has a chance of failing the roll and taking full damage, as well as a chance of success. Effectively, this is an attack with no defense, but a roll-based chance to succeed and to fail, to which I consider the closest analogy an activation roll/requires a roll limitation.

[dsatow]

side note:

A large area of effect accurate attack would require a larger dive for cover roll.  a 4m accurate attack would require a dive for cover by 2.  a 8m accurate attack would require a dive for cover by 4.  a 16m by 8.  etc.  So there is a little bit of a reason to increase the area of effect.

[Cantriped]

Although it isn't outright prohibited Champions Complete and ​Fantasy Hero Complete​ strongly discourage placing Accurate on larger than 1m radii.

 

Also I very much like the idea of using AVAD as the basis to emulate D&D style Save-or-Suck spells. Such spells typically ignore the character's Armor Class (and therefore Armor) in exchange for being defended against by a Characteristic Roll. I can even see doing so being entirely legal in CC/FHC as well. Except that "The Target Fails A Characteristic Roll" would fall under the Rare Frequency (because it is a specified condition not listed), and it would be NND (unless the author came up with a system equating various levels of success to levels of Damage Reduction), and such powers would frequently have to take Does Body to remain effective.

[Hugh Neilson]

If I'm paying the points to have an attack work outside of "rare" conditions, I don't expect it will fail often. A base characteristic roll will fail 62.5% pf the time (11-) or more often. If I'm paying more than I would pay for a power with an 11- activation roll (fails only 37.5% of the time), that's not a remotely fair price.

[Cantriped]

I didn't argue it was "fair"... simply legal. One advantage to using a Characteristic Roll as a defense is that you can link it to (or use it following) a Change Environment power which imposes penalties to that Characteristic Roll to significantly increase the chances of that attack being successful. Another advantage is that a power with an Activation Roll still has normal defenses (which decrease it's effectiveness under all circumstances), while a power using a Characteristic Roll as it's defense never suffers from reduced effectiveness if it is successful.

[Christopher R Taylor]

A base characteristic roll will fail 62.5% pf the time (11-) or more often. If I'm paying more than I would pay for a power with an 11- activation roll (fails only 37.5% of the time), that's not a remotely fair price.

 

 

 

Depends on the circumstances and the alternative.  For +1/4 you can have a power never miss unless someone makes a roll you define and the GM approves, no matter what their DCV is.  They could have 800 PD and it takes effect, unless they make the roll, for just a slightly higher price.  Why isn't it more?  Because as you point out they have a pretty good shot at making the roll.  You want the roll harder?  Costs more.

[Hugh Neilson]

I didn't argue it was "fair"... simply legal. One advantage to using a Characteristic Roll as a defense is that you can link it to (or use it following) a Change Environment power which imposes penalties to that Characteristic Roll to significantly increase the chances of that attack being successful. Another advantage is that a power with an Activation Roll still has normal defenses (which decrease it's effectiveness under all circumstances), while a power using a Characteristic Roll as it's defense never suffers from reduced effectiveness if it is successful.

Let's shop and compare:

 

4d6 AVAD (smell PER roll eliminates damage, +1/2) does BOD (+1) is a 50 AP, 50 Real Point power. If my target makes a smell PER roll, he takes no damage. Most targets will make that roll on an 11- to 13-, so each attack fails between 62.5% and 83.8% of the time.

 

4d6 AVAD (Smell Flash Defence; all or nothing +1), does BOD (+1), Requires a roll 14- (-1/2; each phase -1/2, 14- +3/4 = -1/4) 60 AP, 48 RP

 

Same effect, but the second build succeeds over 90% of the time (unless the target actually has Smell Flash Defense - how common is that?), instead of succeeding somewhere between 37.5% and 16.2% of the time.

 

Which power will be more effective over time?