Are warships too fragile in GURPS?

David L Pulver · 02-02-2008, 01:14 AM

Realistically speaking, you have several types of damage if using HP.

The version I have long wanted to use for GURPS splits the HP into two values: a "to kill" number and a "cumulative damage" number.

(1). HTK
This simulates the shot that penetrates armor and hits something important, taking it out. Studies of modern naval warfare in the missile age in which vessels that were lightly armored faced a single bomb or missile suggest that survivability scaled with the length of the vessel or the cube root of mass. This was also the basis of GURPS hit points. It reflects the odds of a shot, blow, etc. penetrating and hitting a vital part (brain, major organ, bone, etc.) whose strength is generally also scaled with overall length.

-> In humans, a hit to a vital organ, joint, etc.
-> In vehicles, a hit to an important part of a machine.
This probably scales roughly with length, and follows the GURPS formula.

For accuracy, this should probably be modeled as:
"Calculate HP normally, but it is then read as "HTK."
"Any time damage exceeds HTK/4, make a HT roll or be disabled. Modifiers: -1 if damage exceeds HTK/2, -2 if it exceeds HTK, -4 if it exceeds HTKx2, and -3 if the vehicle contains enough dangerous fuel or explosives to be volatile.

For most vehicles, assign a HT based on how well they're put together: attention paid to damage control, provision of firefighting gear, how tightly vulnerable components are packed, compartmentalization, etc., etc. Around 10-13 for average designs. That way you can simulate the difference between a russian and a US tank, for instance.

Targets that are utterly HOMOGENOUS ignore this result.

(2). Crew Casualties
Use the usual rules in 4e for penetrating the ship and taking out crews.

(3). Cumulative Damage.
Eventually, enough holes will kill anything, even a zombie or a wooden ship. Since GURPS damage is somewhat nonlinear, it's not fair to use weight directly - we'll have to scale it a bit. I suggest you assume HP = weight in lbs. (or 2,000 per ton) then find the linear measurement of SM, convert to yards, and divide by that value. Thus, humans (2 yards) have 150 HP have 75 HP; a 3,000 ton ship that is 150 yards long has 40,000 HP.

At 0 HP, start making HT rolls to avoid falling apart/keep going as usual. Modify this for ships at sea - as water will will be flooding etc.

Track damage separately for limbs etc. giving them proportionately HP.

(4). Surface Damage
For things like "how many surface weapon batteries/cannon/Traveller turrets: did I kill, probably assign them based on a fraction of the cumulative damage

02-02-2008, 01:14 AM	#13
David L Pulver AlienAbductee Join Date: Aug 2004 Location: In the UFO	Re: Are warships too fragile in GURPS? Realistically speaking, you have several types of damage if using HP. The version I have long wanted to use for GURPS splits the HP into two values: a "to kill" number and a "cumulative damage" number. (1). HTK This simulates the shot that penetrates armor and hits something important, taking it out. Studies of modern naval warfare in the missile age in which vessels that were lightly armored faced a single bomb or missile suggest that survivability scaled with the length of the vessel or the cube root of mass. This was also the basis of GURPS hit points. It reflects the odds of a shot, blow, etc. penetrating and hitting a vital part (brain, major organ, bone, etc.) whose strength is generally also scaled with overall length. -> In humans, a hit to a vital organ, joint, etc. -> In vehicles, a hit to an important part of a machine. This probably scales roughly with length, and follows the GURPS formula. For accuracy, this should probably be modeled as: "Calculate HP normally, but it is then read as "HTK." "Any time damage exceeds HTK/4, make a HT roll or be disabled. Modifiers: -1 if damage exceeds HTK/2, -2 if it exceeds HTK, -4 if it exceeds HTKx2, and -3 if the vehicle contains enough dangerous fuel or explosives to be volatile. For most vehicles, assign a HT based on how well they're put together: attention paid to damage control, provision of firefighting gear, how tightly vulnerable components are packed, compartmentalization, etc., etc. Around 10-13 for average designs. That way you can simulate the difference between a russian and a US tank, for instance. Targets that are utterly HOMOGENOUS ignore this result. (2). Crew Casualties Use the usual rules in 4e for penetrating the ship and taking out crews. (3). Cumulative Damage. Eventually, enough holes will kill anything, even a zombie or a wooden ship. Since GURPS damage is somewhat nonlinear, it's not fair to use weight directly - we'll have to scale it a bit. I suggest you assume HP = weight in lbs. (or 2,000 per ton) then find the linear measurement of SM, convert to yards, and divide by that value. Thus, humans (2 yards) have 150 HP have 75 HP; a 3,000 ton ship that is 150 yards long has 40,000 HP. At 0 HP, start making HT rolls to avoid falling apart/keep going as usual. Modify this for ships at sea - as water will will be flooding etc. Track damage separately for limbs etc. giving them proportionately HP. (4). Surface Damage For things like "how many surface weapon batteries/cannon/Traveller turrets: did I kill, probably assign them based on a fraction of the cumulative damage __________________ Is love like the bittersweet taste of marmalade on burnt toast?