This is similar to Hair, but also unique in it's own way

Weapons can be rather difficult to pinpoint. Any weapon your OC has must be in accordance with timeline, cultural rules about weapons, and technology. You don't want laser guns in a society similar to Biblical Israel, unless that society has an advancements in technology similar to Star Wars and Star Trek.

Some cultures it is easier to get and obtain a weapon than others. Since Israel is surrounded by people who want to cause God's People harm, almost every Israeli has a weapon and serves in the military. Though America doesn't have any enemies on our borders, (although illegal immigrants are a real problem), her citizens can choose whether to own a weapon or not. Americans can choose to own a weapon; if Israeli's had that choice, they would be destroyed by their enemies. If the government in the society says certain weapons are ok, but your OC is found with a weapon not legalized by their government, your OC will go to jail.

Technology is also a big thing. Whose going to use a spear when people are shooting flame thrower or energy-blast based guns at you? Unless your OC is similar to Rambo or Arnold Schwarzenegger's Terminator, your setting your OC up for failure. Almost everyone in Star Wars and Star Trek have laser guns or some awesome technology-hyped knife/bladed weapon; if your cutlure has the technology, the chances are citizens weapons are gonna match the level of technology available to the general public.

Class, once again, holds a huge role in your OCs weaponry. The better the money, the better the weapon. Unless your OC steals a weapon from a rich class person, there weapon should match their class and place in society. Military = the best weapons available. A simple farmer = probably a shovel, a axe, a pitchfork or maybe a gun they use to shoot birds down. Some accessories can hide weapons within them, just to point out for all you spy/super agent loving, OC makers.

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Accessories are also affected by this. If the societies form of phone is a hologram projector, chances are your OC will own a hologram projector in place of a modern day phone. According to technology, your OC may or may not have something made out of metal or plastic. If there aren't any modern factories in this time setting, chances are all your accessories are being made by a expert on how to make a particular accessory (blacksmith can also make bracelets and earrings; jewellers can make better bracelets, earrings and necklaces with precious gems).

Keep in line the timeline as well. If your OC is living in WW2, there not going to have a phone or a modern day bicycle, (or even a fidget spinner). There were bicycles and simple made scooters, but modern day phones didn't existed back then. (There were phones, but they weren't like ours these days.).

Speaking of WW2, keep in mind any wars that may go down in the fanfiction or story your writing. During WW2, metal and other needed materials were gathered up and used to help the war effort; if your OC owns a golden ring from their deceased father and the military is ordering that all gold need to be used in a warm effort, your OC should hide the ring and not keep it wear it visibly. Unless your OC is completely ok with throwing a heirloom away for the war effort, your OC will need to hide the partical accessroy somewhere safe, somewhere will no one will find it..... (Until someone does find it, lol)

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One more thing can also effect what type of weapon or accessory a OC has; your OC itself. Let's say your OC doesn't believe in violence, such as Sensei Garmadon in Ninjago season 3. Due to his evil past as Lord Garmadon, Sensei Garmadon didn't believe in violence. Even when Nindroids attacked his monastery (season 3, episode 2), Sensei Garmadon didn't fight them. Instead the Sensei used a staff (and the art of the silent fist) to avaid his enemies, letting his "opponents fight themselves". Though it is important to note that after his son was captured by the bad guy at the time, Sensei Garmadon decided that "all bets were off"; Garmadon would get his son back, no matter who he had to fight.... Including his brother, Sensei Wu.

Anyway, off of that! Your OC doesn't need to use a conventional weapon to "fight" his or her opponents. Heck, if there really good at sneaking around, they don't need a weapon at all!

Same goes for accessories. If a OC hates germs, they will most likely need gloves to cover their hands in order to go about a normal day. If your OC is a vampire that can survive daylight but burn under the sun's rays, sunblock, a floppy hat and sunglasses will have to be this OCs everyday accessories (Marvis from the Hotel Transylvania series).

Keep in mind everyone your OC is, in order to set up the correct weapon and accessories.