Rules for building items

midnight77 · 09-21-2020, 06:47 PM

I've looked over the rules for inventing things in GURPS, but are there rules for building already existing items? Say a player wants to use Machinist and Armory(Small Arms) to build a copy of a gun from raw materials, or a player wishes to smith their own sword. Are there rules for this?

Varyon · 09-21-2020, 08:06 PM

Quote:

Originally Posted by midnight77

I've looked over the rules for inventing things in GURPS, but are there rules for building already existing items? Say a player wants to use Machinist and Armory(Small Arms) to build a copy of a gun from raw materials, or a player wishes to smith their own sword. Are there rules for this?

Low Tech Companion 3 has some rules. They basically amount to paying for raw materials, then making up for the rest of the cost with labor.

Ejidoth · 09-21-2020, 08:40 PM

Raw materials are usually roughly 20% of cost per B515, if you don't want to get into the precision of Low Tech Companion 3.

If you don't mind slightly unrealistic results, you could take that as a starting point, then use the Production rules for Inventions on B474, which says producing something after the invention and prototyping has already been handled takes half as long as producing a prototype.

Or do it a bit more like LTC3 and just figure out what a craftsman makes per day based on monthly income and use that time to fill in the 80% of cost that raw materials didn't cover.

Varyon · 09-22-2020, 04:21 AM

While potentially cinematic, for the labor rate, an option is to assume skill 12 in an Average skill is good for an Average wage for the skill’s TL (divide monthly wage by 25 to get daily, or 200 to get hourly). Every +1 to skill is +1 step on the Size and Speed/Range Table to wage (and thus rate), every -1 to skill is -1 SSR. For an Easy skill, treat it as though it were two levels lower (skill 14 gives an Average wage); for Hard and Very Hard, treat as one or two levels lower, respectively. This gets results comparable to what is seen (wage-wise) in LTC3, but having this essentially let masters do apprentice work in a fraction of the time may be unrealistic.

AlexanderHowl · 09-22-2020, 05:54 AM

Dividing by 25 assumes that people are working 25 days a month, which is not necessarily historically accurate (that leaves only 65 days for holidays, vacation, religious observation, etc.). It is also counterproductive, as productivity decreases when workdays exceed 20 days a month. For example, when you examine American workers and control for increased education and improvements in technology, their productivity has actually decreased over the last five decades, despite working more hours and more days.

When it comes to hourly rates, I would also divide by 6 per day (120 by month) instead of by 8 per day (160 per month). People need an average of 15 minutes per hour for rest and socialization (this includes meal breaks) or else their hourly productivity declines, so you actually only get 6 hours per day of productivity. Anything beyond 6 hours of actual work per day results in lower hourly productivity.

Now, this does not include farmers, as farming is generally long periods of low impact activity interspaced with short periods of high activity. A farmer worked every day, but they probably averaged only 4 hours per day of productive work, as a lot of it depended on waiting around. Historically, they would use their waiting around time for personal chores, as work and home were often the same place.

If you want a historically accurate gauge, I would probably divide monthly income by 20 for daily productivity (while people might work more days, their daily productivity declines because of higher levels of fatigue). Hourly rates are probably daily rates divided by 6 rather than 8 (once again, while people may work more hours, their hourly productivity declines because of higher levels of fatigue). Thus, I would divide monthly production by 20 to get daily production and daily production by 6 to get hourly production (while people might work more days and longer hours, it is balanced by lower daily and hourly production).

09-21-2020, 06:47 PM	#1
midnight77 Join Date: Aug 2013	Rules for building items I've looked over the rules for inventing things in GURPS, but are there rules for building already existing items? Say a player wants to use Machinist and Armory(Small Arms) to build a copy of a gun from raw materials, or a player wishes to smith their own sword. Are there rules for this?

09-21-2020, 08:40 PM	#3
Ejidoth Join Date: Jul 2009	Re: Rules for building items Raw materials are usually roughly 20% of cost per B515, if you don't want to get into the precision of *Low Tech Companion 3*. If you don't mind slightly unrealistic results, you could take that as a starting point, then use the Production rules for Inventions on B474, which says producing something after the invention and prototyping has already been handled takes half as long as producing a prototype. Or do it a bit more like LTC3 and just figure out what a craftsman makes per day based on monthly income and use that time to fill in the 80% of cost that raw materials didn't cover.

09-22-2020, 04:21 AM	#4
Varyon Join Date: Jun 2013	Re: Rules for building items While potentially cinematic, for the labor rate, an option is to assume skill 12 in an Average skill is good for an Average wage for the skill’s TL (divide monthly wage by 25 to get daily, or 200 to get hourly). Every +1 to skill is +1 step on the Size and Speed/Range Table to wage (and thus rate), every -1 to skill is -1 SSR. For an Easy skill, treat it as though it were two levels lower (skill 14 gives an Average wage); for Hard and Very Hard, treat as one or two levels lower, respectively. This gets results comparable to what is seen (wage-wise) in LTC3, but having this essentially let masters do apprentice work in a fraction of the time may be unrealistic. __________________ GURPS Overhaul

09-22-2020, 05:54 AM	#5
AlexanderHowl Join Date: Feb 2016	Re: Rules for building items Dividing by 25 assumes that people are working 25 days a month, which is not necessarily historically accurate (that leaves only 65 days for holidays, vacation, religious observation, etc.). It is also counterproductive, as productivity decreases when workdays exceed 20 days a month. For example, when you examine American workers and control for increased education and improvements in technology, their productivity has actually decreased over the last five decades, despite working more hours and more days. When it comes to hourly rates, I would also divide by 6 per day (120 by month) instead of by 8 per day (160 per month). People need an average of 15 minutes per hour for rest and socialization (this includes meal breaks) or else their hourly productivity declines, so you actually only get 6 hours per day of productivity. Anything beyond 6 hours of actual work per day results in lower hourly productivity. Now, this does not include farmers, as farming is generally long periods of low impact activity interspaced with short periods of high activity. A farmer worked every day, but they probably averaged only 4 hours per day of productive work, as a lot of it depended on waiting around. Historically, they would use their waiting around time for personal chores, as work and home were often the same place. If you want a historically accurate gauge, I would probably divide monthly income by 20 for daily productivity (while people might work more days, their daily productivity declines because of higher levels of fatigue). Hourly rates are probably daily rates divided by 6 rather than 8 (once again, while people may work more hours, their hourly productivity declines because of higher levels of fatigue). Thus, I would divide monthly production by 20 to get daily production and daily production by 6 to get hourly production (while people might work more days and longer hours, it is balanced by lower daily and hourly production).