One of the fastest ways to break immersion is when every shop feels like a game menu. A vendor should not sell everything. A shop should reflect what that person does, what they can get, what they can store, what they understand, and who they sell to. A car vendor should not randomly have a .50 cal rifle. A normal gun shop should not casually stock advanced energy weapons unless there is a strong reason. Trade should feel practical, local, and believable.
The easiest rule is this:
A vendor sells what fits their trade, supply line, storage, and customer base.
If an item does not fit those things, it usually should not be there.
Before putting an item in a shop, ask:
What is this vendor actually known for?
A gun seller sells guns, ammo, parts, slings, cleaning kits, and maybe armor.
A mechanic sells tires, belts, hoses, batteries, filters, scrap parts, tools, and fuel cans.
A doctor sells medicine, bandages, antiseptic, splints, syringes, and chems.
A general trader sells broad survival goods, but not highly specialized military gear.
If the item does not match the vendor’s trade, it usually does not belong there.
How do they get it?
A frontier gunsmith can get hunting rifles, revolvers, shotgun shells, and reloaded ammo if that is what moves through the region.
A mechanic can get wrecked parts, scrap engines, tires, and salvaged vehicle frames because that is what scavengers bring in.
High-end energy weapons need rare parts, cells, tools, and technical skill. If none of that exists nearby, they should be rare or absent.
If the vendor cannot realistically acquire the item, they should not have it.
Can they safely keep it?
A roadside trader can store food, rope, lanterns, and simple ammo.
That same trader probably cannot safely store plasma charges, military explosives, or unstable power cells.
A small vehicle yard can keep engine blocks, fuel drums, and scrap, but not delicate lab equipment or rare prototype weapons.
If storing it would be dangerous, expensive, or impractical, the vendor likely will not stock it.
Who buys from them?
A gun shop sells to hunters, guards, caravan hands, and mercs.
A vehicle yard sells to drivers, mechanics, scouts, and convoy crews.
A clinic sells to the wounded, addicts, settlers, and travelers.
A black market contact sells to smugglers, raiders, and people with money who want illegal goods.
A shop should stock what regular customers actually need.
A shop is not an item list. It is a business trying to survive.
That means a vendor usually wants to carry:
things that sell
things they understand
things they can replace
things they can store
things that fit their reputation
They usually avoid carrying:
goods too rare to replace
goods too dangerous to keep
goods too specialized to sell
goods they cannot judge or repair
goods that bring the wrong kind of attention
This is the broadest shop, but still not a magic inventory.
Good stock:
food, water, rope, tarps, blankets, lanterns, batteries, cookware, scrap tools, cheap clothes, bags, filters, common meds, maybe simple ammo
Might have:
one or two basic guns, a knife rack, binoculars, maps, a cheap radio, work gloves
Usually should not have:
heavy weapons, rare armor, advanced energy weapons, military explosives, vehicle engines
A general trader sells survival.
Good stock:
pistols, revolvers, shotguns, hunting rifles, common carbines, ammo, magazines, slings, scopes, gun oil, spare parts, reload tools, holsters, basic armor
Might have:
military surplus rifles, a rare sniper rifle, a repaired automatic weapon, old grenades under the counter
Usually should not have:
vehicle parts, medical gear, plasma rifles, missile launchers, anti-materiel rifles, experimental weapons
A normal gun shop sells practical ballistic weapons first.
Good stock:
laser pistols, charge packs, focusing lenses, spare emitters, cooling sleeves, circuit parts, insulated tools, repair gear
Might have:
laser rifles, rare cells, repaired pre-war tech, unstable surplus parts
Usually should not have:
stacks of normal hunting rifles, farm tools, wagon axles, canned food
Energy weapons should come from people built around that trade.
Good stock:
tires, hoses, belts, spark plugs, filters, radiators, batteries, axles, lights, patch kits, fuel cans, tools, chain, towing gear, scrap panels, doors, mirrors, seats, reinforced bumpers
Might have:
armor plating for vehicles, turret mounts, spare engines, wrecked chassis, convoy cage parts
Usually should not have:
.50 cal rifles, sniper ammo, energy pistols, military grenades, surgery kits
A vehicle seller may sell mounts for weapons, but usually not the rare gun itself unless they are also an arms dealer.
Good stock:
bandages, antiseptic, painkillers, splints, antibiotics, syringes, inhalers, med bags, burn cream, water purifier tabs
Might have:
combat stimulants, detox kits, field surgery tools, rare pre-war meds
Usually should not have:
battle rifles, missiles, engine parts, advanced armor
A medical shop sells care, not battlefield loot.
Good stock:
helmets, boots, chest rigs, old uniforms, armor plates, pouches, belts, packs, gas masks, canteens, entrenching tools
Might have:
surplus rifles, riot shields, old grenades, damaged optics, military manuals
Usually should not have:
engine parts, food crates, exotic energy weapons, lab gear
This is where exceptions live, but even here there should be logic.
Good stock:
contraband ammo, forged papers, stolen meds, silencers, lock tools, restricted chems, hidden pistols, illegal parts
Might have:
one energy weapon, a stolen officer’s sidearm, a crate of rare ammo, smuggled tech
Usually should not have:
everything at once
The black market is not “all rare items.” It is specific illegal goods someone risked moving.
Shops can overlap a little, but only at the edges.
A gun shop may sell boots and field rations.
A mechanic may keep a shotgun under the counter.
A general trader may have one hunting rifle.
A doctor may carry a revolver for defense.
That overlap feels real.
What breaks immersion is when overlap becomes total and every vendor sells everything.
A weird item can show up in the wrong shop, but there should be a reason.
A mechanic has a .50 cal rifle because it came mounted on a wrecked convoy truck and nobody local can afford it.
A gunsmith has one laser pistol because a caravan guard traded it for debt.
A doctor has a military sidearm because a patient paid in gear.
A trader has odd ammo because a scavenger sold it cheap.
One strange item is flavor. Ten strange items is nonsense.
Before adding an item, ask:
Would this vendor buy it?
Would this vendor know what it is worth?
Would this vendor have customers for it?
Would this vendor be able to store it?
Would this vendor be able to replace it?
If most answers are no, it should not be there.
A car vendor sells:
a .50 cal rifle, plasma grenades, fusion cells, combat armor, antibiotics, canned peaches, and three engine blocks.
This feels like a loot menu.
A car vendor sells:
tires, hoses, belts, patch kits, fuel siphons, towing chain, battery packs, scrap panels, reinforced bumpers, mirrors, tools, and one sawed-off shotgun for protection.
This feels believable.
Do not ask, “What cool loot can I put in this store?”
Ask, “What does this person actually make a living selling?”
That is what makes trade feel real. When every vendor has a clear lane, shops gain identity, rare items feel special, and players learn where they actually need to go to find what they want.