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Old 01-05-2021, 12:53 PM   #31
Anders
 
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Location: Gothenburg, Sweden
Default Re: Melding Beam Weapons and Guns

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Originally Posted by johndallman View Post
I had a powerful photographic flashgun that had slight, but detectable recoil. This was due to it heating up the air in front of its output window, but you'd get a similar effect with a powerful pulsed laser.
That's a good point. I was thinking photon momentum. Sorry.
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Old 01-05-2021, 02:05 PM   #32
Varyon
 
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Default Re: Melding Beam Weapons and Guns

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Originally Posted by johndallman View Post
I had a powerful photographic flashgun that had slight, but detectable recoil. This was due to it heating up the air in front of its output window, but you'd get a similar effect with a powerful pulsed laser.
I suspect it would still have to be extremely powerful for this to occur, or be focused very close to the emitter. From what I understand, any sort of laser with decent range is rather unfocused at the emitter, but focuses down to a very small area on the target. You need a laser powerful enough that it seriously heats the air when unfocused, and something like that is going to be really powerful when it is focused.

Of course, I'm far from a physicist, so take the above with an appropriate quantity of salt.
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Old 01-05-2021, 04:26 PM   #33
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Default Re: Melding Beam Weapons and Guns

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Originally Posted by Varyon View Post
I suspect it would still have to be extremely powerful for this to occur, or be focused very close to the emitter. From what I understand, any sort of laser with decent range is rather unfocused at the emitter, but focuses down to a very small area on the target. You need a laser powerful enough that it seriously heats the air when unfocused, and something like that is going to be really powerful when it is focused.

Of course, I'm far from a physicist, so take the above with an appropriate quantity of salt.
On the one hand, it seems odd to expect a laser weapon to put out less energy than a photography flash.

On the other, depending on the technology and spectrum of the flash it might manage to cause much more heating at the output for a given energy, due to putting a lot of energy into wavelengths that are absorbed either by the window or very quickly in air.

I don't think it matters much how concentrated the light is at the emitter unless it's so concentrated it's flashing the air to plasma or something. So long as you're not doing something like that, the same energy more spread out would produce less pressure, but only in proportion to the increased area. So it would yield the same produced force. (To a really basic approximation.)
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Old 01-09-2021, 03:27 PM   #34
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Default Re: Melding Beam Weapons and Guns

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Originally Posted by Anders View Post
you can use your gun's laser sight on someone with full skill,
but move the laser downstairs and amp it up and you are suddenly at -4 to skill.
I don't think you even make skill rolls for aiming unless you're using Cole's On Target system from pyramid 3/77

Laser sights (ie did I get a bead on the guy or not) are an interesting consideration since unlike pure-vision aiming there is an observable indication that someone's being aimed at.

There's clearly incentive though: if attacker observes the laser dot then they know their aim is good and can remain stable and attack.

Cole has DX-based gun roles for aiming because I believe that reflects actually lifting the arm and leveling the weapon at the target in preparation.

Aiming clearly has a vision component (hand-eye coordination) but then so does a lot of DX stuff, we have vision penalties apply to DX as well as Per.

Would be kinda cool if there was some way to have good perception benefit this (or bad perception detract), like being a setup skill, similar to how in "Dodge This" Cole had a Vision check before making active defenses.

Actually seems strange when I look at defaults how guns all seem to be DX-4 while Throwing is DX-3. I get that throwing is a much more instinctive skill but pointing something in a direction still seems like an easier skill...

It's not an issue close-up as guns alone can take the +4/+4 for AOA:Determined / Telegraphic Attack at melee ranges while throwing weapons can't, while at long ranges, throwing weapons incur range penalties sooner... but you still have the weirdness at long range that I can somehow aim better whipping a baseball than with a gun.

Actually maybe that's what Acc does because throwing weapons lack Acc? Not aiming means not enjoying the Acc so you're just snap-shotting in which case I could see how guns could fall behind snap-throws.

As for how people aim so well with a laser pointer... given that it's a continuous beam I'm wondering if maybe we should treat that as having some kind of insanely high ROF (like 300+) so that there's just a huge bonus from that?

That could also explain how you could swipe a laser pointer across a room and in theory blind a dozen guys... although there should probably be something in regard to "exposure time" to light needed to do damage to retina.
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Old 01-09-2021, 05:28 PM   #35
Willy
 
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Default Re: Melding Beam Weapons and Guns

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That could also explain how you could swipe a laser pointer across a room and in theory blind a dozen guys... although there should probably be something in regard to "exposure time" to light needed to do damage to retina.
It has a reason why in many nations, including mine the output of laser pointers is capped, some of them go in the 5 Watt range or higher, the time of exposure for eye damage is extremely short. Depending how close you are itīs less than 1/10 of a second. The distance to to the laser is also important. Of course you need to differ between short time blindness, and lasting crippling injuries. Military or police forces want to mark the target, so the output is lower, dangerous for eyes itīs nevertheless. Normally this forces are not interested in a unnecessary high output, because the batteries are draining faster. Some nations build blinding lasers on purpose, or experiment for Spec Op / SWAT Forces with lasers that can switch power output, between target / blinding mode. Also their are experiments with lasers that blink at very high frequency, so that they can trigger epileptic seizures. GURPS High Tech page 181 has further Info about lasers. Because time goes on their are claims by china and russia that they build portable lasers, that are able to shoot down drones.

Last edited by Willy; 01-09-2021 at 05:29 PM. Reason: spelling error added example
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Old 01-10-2021, 08:33 AM   #36
Plane
 
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Default Re: Melding Beam Weapons and Guns

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Originally Posted by Willy View Post
It has a reason why in many nations, including mine the output of laser pointers is capped, some of them go in the 5 Watt range or higher, the time of exposure for eye damage is extremely short.
Depending how close you are itīs less than 1/10 of a second.
The distance to to the laser is also important.
Of course you need to differ between short time blindness, and lasting crippling injuries.
just randomly looking found https://www.ceenta.com/news-blog/can...nter-blind-you

10 seconds is mentioned between1 and 5 milliwatts, so the 1/10 second (that's 1/100 the time) I'm guessing is near 5 watts, which would be 1000x the power?

One mitigating factor would probably be a blink reflex: you just naturally tend to close your eye (or even raise an arm to block your face) when a bright light is shone in it.

Requiring 1/10 a second sounds like you could blind a maximum of 10 eyes in a single second, so RoF 10: but probably less since you're not immediately going from one eye to the next: you're "missing shots" in your ROF as you put the laser on intermediary places...

An alternative to ROF 10 though (which assumes a single shot will blind) would be doing something like ROF 100 and then saying TEN shots is needed to blind.

Damage somehow accrues and must build up quickly I would assume? Or would taking 0.01 second increments an hour/day apart eventually lead to the blinding damage 0.1 second would induce?
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Old 01-10-2021, 10:52 AM   #37
Willy
 
Join Date: Dec 2020
Default Re: Melding Beam Weapons and Guns

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Originally Posted by Plane View Post
One mitigating factor would probably be a blink reflex: you just naturally tend to close your eye (or even raise an arm to block your face) when a bright light is shone in it.
blinking your eyes is very fast, but the lid wouldnīt protect most of it, if the source e.g laser is strong enough, you need more between the retina and the light source to be safe. Itīs like looking at the sun with closed eyes which will blind you to after longer exposure. Even some LED Flashlights are strong enough to damage your eyes.


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Originally Posted by Plane View Post
Damage somehow accrues and must build up quickly I would assume? Or would taking 0.01 second increments an hour/day apart eventually lead to the blinding damage 0.1 second would induce?
I think not, I worked once in a company that did a lot of welding, everyone who got " verblitzt " e.g. had sparks in his vision when looking at something, was strongly discouraged to weld further until healed, mostly next day was enough to avoid lasting damage. According to a master there, little damage would build up over time. Just imagine you scratch yourself a the same point over and over again, it will take time but you will hurt there. Therefore any unhealed damage would add to the next damage. According to my version of wiki it takes less than 250 ms to blink. This means if 0,1 seconds are enough as I understand your calculation this people would be blind, before the blink reflex could safe them. Also according to the same source in 10 - 20 % of all testpersons, the blink reflex isnīt triggered by lightsources. I think pain will do, but then itīs to late anyway.

Last edited by Willy; 01-10-2021 at 10:55 AM. Reason: spelling error added example
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Old 01-10-2021, 02:32 PM   #38
Voren
 
Join Date: Jul 2008
Location: Ontario, Canada
Default Re: Melding Beam Weapons and Guns

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Originally Posted by Anders View Post
I'm thinking of melding the two skills. Currently Guns (Pistol) and Beam Weapons (Pistol) default to each other at -4. Which means that you can use your gun's laser sight on someone with full skill, but move the laser downstairs and amp it up and you are suddenly at -4 to skill. That sounds weird, and GURPS has too many skills anyway. What do you think?
I think this sounds fine, with the usual TL/specialization/familiarity adjustments - provided the general operation of the beam weapon is similar to a gun. Star Wars blaster pistol to Glock? Sure. Glock to Zoltarian Gravitic Degluonator (forelimb mounted, vibration activated) not so much. Even a canonical treatment of a Star Trek TNG hand phaser would seem to justify a different skill, or perhaps a unique specialization (how do they aim? By guess?).
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