Modifying Beam Weapons

[Joel]

I'm thinking of having a 'houserule' to have beam weapons with other rates of fire than those in UT available, basically having more shots per second but having a proportionally lower energy output per shot.

For example; High RoF version of a Semi-Portable Blaster firing 8d(5) 'bolts':

The Heavy Blaster fires 8d(5) bolts at RoF 3 from a D-pack with 20 shots, the Semi-Portable Blaster fires 12d(5) bolts at RoF 3 from an E-pack with 50 shots.

An E-Pack thus has power for 200 8d(5) bolts or 50 12d(5) bolts, so a 12d(5) bolt uses 4x as much power as an 8d(5) bolt.

Could a Semi-Portable Blaster size weapon then be built to use 8d(5) bolts with the same energy output, meaning RoF 12, with the range of the Heavy Blaster (1,200/3,600)? Should it use the Acc of the Semi-Portable blaster or the Heavy Blaster?

Is there some reason the change in RoF should not be proportional to the change in power output per shot?

[Icelander]

Not that I can see.

It's all going to be based on best guesses anyway, so if your proposed modification doesn't trigger a violation of or SoD or that of your players, you're all good.

[Darekun]

Originally Posted by Joel

An E-Pack thus has power for 200 8d(5) bolts or 50 12d(5) bolts, so a 12d(5) bolt uses 4x as much power as an 8d(5) bolt.

3ed had damage specifically proportional to the square root of beam energy, that seems to be kept(as close as rounding) in 4ed.

Originally Posted by Joel

Could a Semi-Portable Blaster size weapon then be built to use 8d(5) bolts with the same energy output, meaning RoF 12, with the range of the Heavy Blaster (1,200/3,600)? Should it use the Acc of the Semi-Portable blaster or the Heavy Blaster?

It should use both the range and Acc of the semi-portable blaster. Other than that, yes.

The theory, based on a mixture of GURPS and RL data:

There's two major components of this kind of energy weapon: the "emitter" and the focal array. The "emitter" varies with the power(beam energy × ROF ÷ efficiency), while the focal array varies with the beam throughput(beam energy × ROF) and range/Acc. Efficiency is generally characteristic of technology and TL. So yeah, it's really that straightforward so long as you leave beam throughput and range/Acc alone. But you do end up with weapons that have a larger focal array than you'd expect for their beam energy. (GURPS generally assumes range/Acc is tuned to beam energy, which certainly doesn't fit the players in either of my two groups it's come up in. It might fit reasonable extrapolation of military doctrine.)

[Langy]

3ed had damage specifically proportional to the square root of beam energy, that seems to be kept(as close as rounding) in 4ed.

In 4E, beam damage is proportional to the cube root of beam energy, not the square root. That's why Spaceships has a 1MJ beam cannon doing 4d of dDamage while a 1GJ beam cannon does 4dx10 dDamage. That's a 1000x increase in beam energy for a 10x increase in beam damage.

[Joel]

Originally Posted by Langy

In 4E, beam damage is proportional to the cube root of beam energy, not the square root. That's why Spaceships has a 1MJ beam cannon doing 4d of dDamage while a 1GJ beam cannon does 4dx10 dDamage. That's a 1000x increase in beam energy for a 10x increase in beam damage.

Well according to my calculator 12/(4^(1/3))=7.5595... so the example seems about right, for accuracy I should change damage to 7d+2(5), as 0.5595*3.5=1.958...

So, to finish the example:

TL 11 Rapid Fire Semi-Portable Blaster (Damage: 7d+2[5] burn, sur; Acc: 15; Range: 2,800/8,400; Weight: 70/Ep; RoF: 12; Shots: 200[5]; ST: 18M; Bulk: -8; Rcl: 1; Cost: $140,000; LC: 1)

other examples:

TL 11 Very Rapid Fire Semi-Portable Blaster (Damage: 5d+2[5] burn, sur; Acc: 15; Range: 2,800/8,400; Weight: 70/Ep; RoF: 30; Shots: 500[5]; ST: 18M; Bulk: -8; Rcl: 1; Cost: $140,000; LC: 1)

TL 11 Rapid Fire Heavy Blaster (Damage: 4d+2[5] burn, sur; Acc: 10+4; Range: 1,200/3,600; Weight: 20/Dp; RoF: 15; Shots: 100[5]; ST: 10+; Bulk: -6; Rcl: 1; Cost: $40,000; LC: 1)

TL 11 Rapid Fire Rainbow Strike Laser (Damage: 11d[3] burn; Acc: 18; Range: 50,000/150,000; Weight: 500/Fp; RoF: 20; Shots: 900[5]; ST: 27M; Bulk: -10; Rcl: 1; Cost: $250,000; LC: 1)