Random Attack

[Diomedes]

How would one stat an attack that can have one of several effects, but which one occurs is not under the player's control?

My intention is a toxin that would have varying effects, from Moderate Pain up to Coma.

[vierasmarius]

For the toxin you could just build it as an Affliction with a Secondary Effect - so basic failure would inflict Effect A, but failure by a large margin (not sure the exact amount, IDHMBWM) would add Effect B. I think you can use an Innate Attack as the carrier for it too.

Not sure if it's RAW, but you could build a set of Alternative Attacks that are selected from at random. Don't know what the modifier would be for it though. For example, a powerful attack with a weaker random alternate would be less useful than just the main attack on its own. Someone with more experience building powers will have to help on that one.

[Sunrunners_Fire]

Originally Posted by vierasmarius

For the toxin you could just build it as an Affliction with a Secondary Effect - so basic failure would inflict Effect A, but failure by a large margin (not sure the exact amount, IDHMBWM) would add Effect B. I think you can use an Innate Attack as the carrier for it too.

Not sure if it's RAW, but you could build a set of Alternative Attacks that are selected from at random. Don't know what the modifier would be for it though. For example, a powerful attack with a weaker random alternate would be less useful than just the main attack on its own. Someone with more experience building powers will have to help on that one.

Accessibility: Only Works a Percentage of the Time
(GURPS Powers, page 99)

... Assign each effect a percentage range (adding up to 100%), then either roll percentile dice to see which one "works", or determine the percentage chance of rolling each result of the 3D6 standard and check against the chance-to-work as if rolling percentile dice.

[Anaraxes]

The Accessibility is a little too much of a discount, as it assumes a chance of failure and completely wasting your turn. In this case, just because one attack "fails" doesn't mean you've failed to attack the target.

If all the AAs have the same cost, the only limitation I can see is some loss of utility from not being able to choose the attack most suited to a target with particular vulnerabilities. On the other hand, it doesn't cost you the usual turn to switch to a different AA, and the bad guys can't observe your attack and learn how to counter it. I'd start with calling it a 0% feature of the set of AAs.

[Bruno]

Originally Posted by Anaraxes

The Accessibility is a little too much of a discount, as it assumes a chance of failure and completely wasting your turn. In this case, just because one attack "fails" doesn't mean you've failed to attack the target.

You are, however, paying full price, not AA price, for each ability, and you are Linking them together so you can trigger them all at once. Or at least that's how I'd do it. At which point I think it's actually quite fair because even if they all would work out to 100 points if they work all the time, you'll be paying probably close to or over 200 points for the mess as your maximum reduction is -50% for infinitesimally rare chances.. and then you add the Link.

Your simplest case, a choice between two powers, Fire and Ice themed respectively, would be -20% and -20%, plus on both the +10% Exclusive Link. Net -10% on both, so for two 100 point abilities, 50%/50% chance of which one goes off, you're paying 180 points.

It's unpredictable for YOU, but your enemy has NO CLUE what you'll pull out of your hat either. But still, if anything, that's overpriced.

EDIT: If you did make it an AA, I think I'd still require the Link to explain that something still goes off. So your main power (using the above example, only two powers) is 90 points, and the alternate is 18. So the total is 108 points.
For three powers, the Accessability is -25%, plus the exclusive Link is a net -15%. So for the array of 100 point alternate abilities, the main power is 85 points, and each alternate is 17 points, for a total of 119 points if you put them in an AA. 255 if you don't which is crazy expensive considering.

For four powers, the accessability is -30%, plus the Link for a net -20%. For the AA array, the price is 80 + (3*80/5) = 128 points. 320 without the AA.

For Five powers, there's no additional discount, so it's 80 + (4*80/5) = 144 points (400 without the AA).

It's really looking like the AA produces a fairer price.

[Anaraxes]

Actually, I was thinking more along the lines of the one base cost (highest if they're not equal, of course). One 50-point attack, or six "50-point" attacks, the exact one of which is selected by a d6. I'm not sure the pros and cons of the randomization in this model is a net limitation or enhancement. I'd try it at base cost and see how it works out.

Linking six full-price attacks together would have them ALL potentially hit. You could discount each attack with Accessibility to reduce the odds that they actually work, but then you need roll the chance of each separately. Maybe all misses, maybe six hits. This is an interesting power as well, but a little different feel than the first one.

For double cost, you'd get the 50-point attack plus five AAs. The exact AA could be selected by the d6. For fun, you could delay that roll until the attack was resolved, rather than at the point the AA was set. This model somewhat conflicts with the requirement to take time to switch your AA, especially since it costs extra.

[Not another shrubbery]

Originally Posted by Anaraxes

On the other hand, it doesn't cost you the usual turn to switch to a different AA, and the bad guys can't observe your attack and learn how to counter it.

Remember that switching between Alternate Attacks is a free action.

Originally Posted by Anaraxes

I'm not sure the pros and cons of the randomization in this model is a net limitation or enhancement. I'd try it at base cost and see how it works out.

Under what conditions would not being able to choose your attack be an enhancement? I cannot come up with anything that balances out with the drawback of not being able to match your attack to best fit the circumstances.

[Bruno]

Originally Posted by Not another shrubbery

Remember that switching between Alternate Attacks is a free action.Under what conditions would not being able to choose your attack be an enhancement? I cannot come up with anything that balances out with the drawback of not being able to match your attack to best fit the circumstances.

Compared to having one fixed attack, it can be advantageous as your enemies can't set up defenses against that one attack type.

It's obviously disadvantageous compared to being able to choose which of six you fire, and it's obviously disadvantageous compared to firing all six at once.

EDIT: Having writen that, that clarifies a few things for me: It should definitely cost less than six attacks Linked together, and It should cost less than just making an Alternate Ability out of the six attacks.

[Anaraxes]

our enemies can't set up defenses against that one attack type

Yes; and you're not completely stuck when you come up against the Monster Immune to Fire (or whatever your theme is). Similarly, there might be out-of-combat side effects that can be occasionally useful, and where it doesn't really hurt to fire off the attack a few times until you get the right result. (Perhaps you're in the desert and want the Water Cannon option to go off, or that Freeze Ray would be handy for making a metal object brittle.)

You can turn the question around and ask, "what's so disadvantageous about not being able to choose the exact form of the attack?" There are similar answers -- how about that Monster Vulnerable to Fire? But the deviation in either direction seems small, and off the cuff, seem roughly balancing to me.

What value of a limitation would you assign, and why? Does it vary with the number of attacks (one of two, one of six, one of sixty, one of six thousand...)?

[Not another shrubbery]

Originally Posted by Anaraxes

Yes; and you're not completely stuck when you come up against the Monster Immune to Fire (or whatever your theme is). Similarly, there might be out-of-combat side effects that can be occasionally useful, and where it doesn't really hurt to fire off the attack a few times until you get the right result. (Perhaps you're in the desert and want the Water Cannon option to go off, or that Freeze Ray would be handy for making a metal object brittle.)

You can turn the question around and ask, "what's so disadvantageous about not being able to choose the exact form of the attack?" There are similar answers -- how about that Monster Vulnerable to Fire? But the deviation in either direction seems small, and off the cuff, seem roughly balancing to me.

What value of a limitation would you assign, and why? Does it vary with the number of attacks (one of two, one of six, one of sixty, one of six thousand...)?

I'm still not seeing any balance. The instances you mention are ones where it is disadvantageous to you to not be able to choose the proper sfx. Out-of-combat might be trivial for most cases, but the potential for wasting time is there. In combat, the delay in getting just the right effect can range from annoying to dangerous for the attacker.

The pricing of such a limiter is not readily apparent to me. It certainly should be increasing as the number of options goes up, but perhaps at a slowing rate, and I think a proper valuation should take into account how different the attack options are. For the ground floor case, where there are two attacks (even if they are quite different), it seems like a minor to trivial limitation, something like a Nuisance Effect.