Jets and Cones

[Johnny Angel]

I'm a bit out of practice with some of the finer details of the GURPS rules. In particular, I have a few questions about how Jets and Cones work and the differences between the two.


Jet

Does a Jet hit multiple people?

For example, if a group of foes are standing in a line, would a jet attack hit them all?


Cone

If I wanted to create a cone attack that was only one yard wide (similar to a Jet), my understanding is that this would make Cone cost +60%. Would this allow for hitting a group of foes standing in a line? (I was unsure if other targets would count as cover.)

Are Cones assumed to expand in width (horizontally) only?




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What I'm trying to do is build an innate attack which pushes enemies away in a manner similar to a Dragonshout from Elder Scrolls: Skyrim. What I'm trying to figure out is how I can make the attack in a manner which hits several people in a line.


Another example which might illustrate what I'm trying to do would be some of the line-shaped draconic breath weapons in D&D. They require everyone in a line to make a save or take damage. Does something like that translate into a GURPS Jet or a GURPS 1-yard Cone?

[Diomedes]

Originally Posted by Johnny Angel

Jet

Does a Jet hit multiple people?

For example, if a group of foes are standing in a line, would a jet attack hit them all?


Cone

If I wanted to create a cone attack that was only one yard wide (similar to a Jet), my understanding is that this would make Cone cost +60%. Would this allow for hitting a group of foes standing in a line? (I was unsure if other targets would count as cover.)

Are Cones assumed to expand in width (horizontally) only?




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My understanding is that you need a Cone to hit multiple targets; a Jet is, per the Basic Set, treated like a melee weapon. It is specifically incompatible with Area Effect and other enhancements that would allow multiple targets.

[simply Nathan]

Originally Posted by Johnny Angel

Jet

Does a Jet hit multiple people?

For example, if a group of foes are standing in a line, would a jet attack hit them all?

Nope, a Jet just goes in a line until it hits the first target, whence it gets interrupted. Thing is, it counts as a melee attack rather than a ranged one for all that implies.

A one-yard width cone would behave that way.

[Diomedes]

Originally Posted by simply Nathan

Nope, a Jet just goes in a line until it hits the first target, whence it gets interrupted. Thing is, it counts as a melee attack rather than a ranged one for all that implies.

A one-yard width cone would behave that way.

Where do you get this? That certainly isn't apparent from the description.

[simply Nathan]

Originally Posted by Diomedes

Where do you get this? That certainly isn't apparent from the description.

A visual description of what it is (a melee attack made up of a narrow stream of whatever, with Reach instead of Range).

[Captain Joy]

Originally Posted by simply Nathan

Nope, a Jet just goes in a line until it hits the first target, whence it gets interrupted. Thing is, it counts as a melee attack rather than a ranged one for all that implies.

A one-yard width cone would behave that way.

Originally Posted by Diomedes

Where do you get this? That certainly isn't apparent from the description.

I would allow a Jet to attack multiple targets, using some type of spraying fire [B409] (house) rule; but I think Nathan is correct in that Jets fall under the unmbrella of "melee attacks", which means you generally attack one target with it.

I agree with everyone else that Cone is the way for the Johnny Angel to go. And the +60% cost is correct.

People behind other people are shielded from cone attacks. EDIT: I stand corrected as per Nereidalbel's post below. If you want to attack several ranks of people, you're looking at an area effect [B102] attack.

[Nereidalbel]

Originally Posted by Captain Joy

I would allow a Jet to attack multiple targets, using some type of spraying fire [B409] (house) rule; but I think Nathan is correct in that Jets fall under the unmbrella of "melee attacks", which means you generally attack one target with it.

Nathan is 100% correct, as the description for Jet says to treat it as a melee weapon with a very long Reach. Thus, all rules for melee attacks apply, and cinematic Techniques can be used. If there's a Technique to allow a weapon with significant Reach to sweep through multiple targets, it could be used for a Jet attack. And if there isn't one, well, make it so.

Originally Posted by Captain Joy

People behind other people are shielded from cone attacks. If you want to attack several ranks of people, you're looking at an area effect [B102] attack.

Not quite. People only count as cover against Cone attacks if they completely screen people behind them. So, unless somebody's torso is a full yard wide, they provide no cover for people behind them.

[Captain Joy]

Originally Posted by Nereidalbel

People only count as cover against Cone attacks if they completely screen people behind them. So, unless somebody's torso is a full yard wide, they provide no cover for people behind them.

Originally Posted by B413

A cone affects everyone within its area, but anyone who is completely screened from the attacker by an object or person is behind cover, which protects normally.

I would rule the a person need not be a full yard wide to screen somebody, especially a smaller person; but these kinds of things are GM's calls.

As far as the Johnny Angel is concerned, if he wants an attack that affects a line of people extending radially out from him, the stock cone attack will not work. Cone (+60%) with cosmic–can not be screened (+100%) is an option, though there might be a cheaper way, e.g. some kind of modified area effect attack. (I made up the "can not be screened". To my knowledge it's not a stock enhancement.) Although, if we're invoking cosmic enhancements, an enhanced jet could be back on the table.

[Johnny Angel]

Originally Posted by Diomedes

My understanding is that you need a Cone to hit multiple targets; a Jet is, per the Basic Set, treated like a melee weapon. It is specifically incompatible with Area Effect and other enhancements that would allow multiple targets.

Originally Posted by simply Nathan

Nope, a Jet just goes in a line until it hits the first target, whence it gets interrupted. Thing is, it counts as a melee attack rather than a ranged one for all that implies.

A one-yard width cone would behave that way.

That's what I had thought, but I was not completely sure.

So, this is what I have so far:

Fus-Ro-Dah! Cone [22]
5D Crushing [25 points]
Double Knockback +20%
1 Yard Wide Cone +60%
No Blunt Trauma -20%
No Wounding -50%
5 Second Recharge -10%
Reduced Range (10) -30%
Increased 1/2D (x10) +15%

If I did this correctly, what the attack does is 5d6 of Basic Damage. This damage does not cause wounds or blunt trauma, so it does not cause actual injury. However, it does cause double knockback; no armor divisor or penetration modifier was needed because knockback is calculated before DR. The area of the attack is 10 yards long and 1 yard wide. After using the attack, it cannot be used again until the 5 second recharge has occurred.

The average damage of 5d6 is 17.5. Assuming a ST10 target, targets would be pushed back 4 yards. (17/8)*2 = 4

This works out the same even if you use the Powers suggestion of treating double knockback as double the dice of damage.
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If I did the same attack as a Jet, it would look like this:

Fus-Ro-Dah! Jet [12]
5D Crushing [25 points]
Double Knockback +20%
Jet +0%
Increased 1/2D (x2) +5%
No Blunt Trauma -20%
No Wounding -50%
5 Second Recharge -10%

In this case, the shape and area and effects of the attack would be the same as described previously, but it would only hit one target.

In theory a character could also have both abilities and purchase the Jet as an alternative version for 3 points (2.4 rounded up.) This would be a total of 25 points for both.

[Johnny Angel]

Originally Posted by Captain Joy

I would rule the a person need not be a full yard wide to screen somebody, especially a smaller person; but these kinds of things are GM's calls.

As far as the Johnny Angel is concerned, if he wants an attack that affects a line of people extending radially out from him, the stock cone attack will not work. Cone (+60%) with cosmic–can not be screened (+100%) is an option, though there might be a cheaper way, e.g. some kind of modified area effect attack. (I made up the "can not be screened". To my knowledge it's not a stock enhancement.) Although, if we're invoking cosmic enhancements, an enhanced jet could be back on the table.

Those are good points.

I was thinking that the benefit of it hitting everyone in a line might be counter-balanced by the drawback of also hitting allies & friendly creatures if they are in the line.

The screening issue is the primary thing that was giving me trouble. Cone seems to imply that even a 1-yard cone fills that 1-yard area. So, I was understanding that as meaning something solid like a hunk of stone or standing behind someone using a tower shield might block the attack, but just standing in front of someone wouldn't.

I had looked at Area Attack as a way to target a line, but that seems to assume a radius around a point.