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ASMRB House Rules

Version 1.5
January 9, 2000



18.0 Lasers

Laser output is of two types: continuous wave (CW) or pulse. In order to describe the damage effects of a laser, the wavelength, power output, and beam diameter must also be known. Various notable laser wavelengths are:

wavelengthband namenotes
< .01 nmgamma ray 
.01 nm - 50 nmX ray 
50 nm -300 nmextreme UVdoes not penetrate atmosphere well
300 nm - 0.3 µmnear UV 
0.3 µm - 1 µmopticalvisual continuum
1 µm - 3 µmnear IRnight vision gear; objects 400 - 500 C (750° - 950° F) radiate here
8 µm - 14 µmfar IRthermal viewers; objects 27° C ( 80° F) radiate here (CO2 = 10.4 µm)
1 mm - 1 cmmillimetermasers, millimetric seekers & radars; < 300 GHz
> 1 cmradioradio, radar, masers; < 30 GHz

The effects are calculated as follows:

CW Lasers

DC (Killing) = log2(power, watts / 1600)
Piercing = 16 - DC
Speed Class = not applicable (already taken into account)
Stun Modifier = (DC / 2) - 2
Damage Range, inches = (beam diameter / wavelength) * 2(DC / 2) / 3000

Pulse Lasers

DC (Killing) = log2(pulse energy, joules / 25)
Piercing = 10
Speed Class = not applicable (already taken into account)
Stun Modifier = (DC / 2) - 2
Damage Range, inches = (beam diameter / wavelength) * 2(DC / 3) / 4000

Example: the Ares MP laser produces a 40 kilojoule pulse of 1 µm wavelength deep red light, 7.5 cm diameter at the 'muzzle.' This will be rolled as a DC 10 Killing Attack (3d6+1 K), 10 Piercing, Speed Class n/a, +3 Stun Modifier, and with a Damage Range of 200 inches. At point blank range, this will penetrate 3.6 cm of mild steel.

18.1 Damage Range for Lasers

All laser weapons have a damage range as calculated in section 18.0. For each doubling of the Damage Range, lasers lose 1 Damage Class, and 2 Piercing:

DC Modifier = log2(actual range, inches / Damage Range)
Piercing Modifier = 2 * log2(actual range, inches / Damage Range)

Example: the Ares MP laser, with a 200 inch Damage Range, will lose 1 DC and 2 Pc in the 201 to 400 inch gate, 2 DC and 4 PC in the 401 to 800 inch gate, etc.


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Document last modified Friday, June 01, 2001