Might be a good idea to add in lots (and I do mean lots) of new tool and raw material objects.
Yes it’s a pipe, but what size of pipe? Hand drill or power drill? Nail or screw or glue? Beaker or flask or test tube?
I think a good way to know how complete the system is, would be to look at how much material and what type of tools you use to create a pipe rifle, which is hopefully much more than the 2 tools and 2 materials it takes now. Then of course create alternate building plans that incorporate the new items. Hardware store with a tool-repair or custom workshop back room; a pharmacy that’s able to synthesize simple chemicals instead of just being a drug-based retail store; a gun store that has a room where the gun range would be, which refills spent casings and repairs guns.
A list of some possible “tool” objects:
Large movable or almost impossible to carry objects, like the steel compactor behind hardware stores:
- Powered… Lathe, Drill Press, Planer, Circular Saw Table, Band Saw, Jig Saw, Industrial Laser/Water cutting machine, industrial sand blaster, 3D Printing/CAD milling machine, Power sheet metal press/roller
- Hand (or rather, Foot) operated… Drill press, jig saw, band saw, etc
Smaller objects that can or must be “attached” to something like a table to work properly, but can be carried with some difficulty:
- Hand metal C-Vise, hand-operated bullet press/pull, hand-operated casing primer punch-out, powered automatic casing reloading machine, Hand saw cutting jig
Hand tools that can be used by themselves, without furniture, and can be carried easily:
- Power/hand drill, power/hand grinder/sander, sand/bb blaster, chisels, files, power circular saw, square and normal ruler, measuring tape, plumb bob, hand clamps, caulking gun, glue gun, socket wrenches, torque wrenches, monkey wrenches…
- Tool “resources” like drill bits, grinding discs, glue sticks, caulk, sand paper, replacement blades, and the long awaited “screws” and “solder” (and flux) which seem to be missing despite screw drivers and soldering irons being everywhere. Tool resources like drill bits would act like attachments to guns do; each use and the attachments also suffer wear+tear.
- Most of the tools we have now already, but altered: Robertson, Philips, Hexagonal screw drivers and experiencing real life frustrations about the wrong type/size!
Only joking on that last one.
Something that should [I]NOT[/I] happen is a “too detailed” situation, where the player cannot continue because “oops I grabbed the wrong set” and then returns to town to find no matching item, and then searches the surrounding area only to discover there isn’t any matching item for the next 2-5 towns. Granted you could get away with it on something like screw drivers if you had another tool like a grinder, “You grind the Octagonal screwdriver into a Philips head” but getting into things like specific sizes (screws are size 5 and you have size 7) or hilarious things like “security screws” is putting too much reliance on the rand-dumb number god to give you something reliably often (you don’t spend 3 days looking for a new sheet of sand paper for your power/hand sander) that you cannot make yourself. If you do, you really have to make sure there’s overlay between items, and that a character who’s “smart” enough can know that “Yeah you can use silicone instead of rubber there” and do new things like cutting up rubber gloves for rubber chunks (which can be melted and poured into a mold) or even actually be able to chop up wool clothing and re-knit themselves wool clothes.
In fact, do that last one as a test of the system you’re working on. Do it now, I need my wool socks and knit wool hat.
Then slowly add in everything until you get the whole system working in v1.0
Edit - Oh, and how do you expect to handle chemistry under the system? I would prevent players attempting to manually mix chemicals, and to avoid uh “Legal issues” with the more explosive chemicals, work the system so it’s based off of a “This is an explosives manual, it can teach your character how to make TNT” and then the player collects sealed jars of chemical elements and chem-lab type tools, and goes directly from raw material to finished product without any in-between states. Last thing anyone wants is for some dumbass to actually attempt to create nitro-whatever and blow themselves up, or worse (succeed, and blow something else up) because, who knows how many times the “Grow awesome crystals!” image macro of “pouring ammonia and bleach together while blowing into the mixture with a straw” has actually hurt or killed someone stupid enough to trust the internet; since it produces chlorine gas. (and I wish DDA would be leveled on that officially, too; not “tear gas” but “toxic gas that will kill you”)