A creative fighting tactic useful by unarmed people in any situation: make what's around you a weapon. Even outside the dangerous environments, there's a lot of stuff to try. Anything can be used as a club if it's sturdy enough, and most hard materials will develop a sharp edge if properly coaxed. For comedy value, go as wacky as you like.

Compare MacGyvering. See also DIY Threat Detection.

Depending on the setting or the characters, there's a lot of options:

• The Bar Brawl — Pool cues (and balls), beer bottles, darts, chairs, stools, Flipping the Table, essentially anything that isn't nailed down.
• In a car — Slow or fast, as long as it's undodgeable, it's quite dangerous. Especially if it's laden with explosives or otherwise prone to combusting in some other manner.
• Construction sites — wrenches, shovels, hammers, hatchets, pipes, bricks, iron bars, boards, pickaxes, paint buckets, blowtorches, aerosol flamethrowers, crowbars, hacksaws, portable drills, power cutters, rivet guns, sharpened metallic roadsign, welding equipment, bulldozers, excavators, trucks, forklifts, chains, gas cylinders, and many other tools.
• In a farm — pitchforks, hoes, shovels, rakes, pesticides, herbicides. Even a tractor.
• At the gym — Hand weights, dumbbells, kettlebells, lighter barbell weights, and other small weights are equally good as both bludgeons and projectiles. Heavier barbell weights might not be easy to throw, but will still hurt like hell if you hit someone in the face or drop it on their toes. Additionally, bereft of weights, a barbell's actual bar can make for a good quarterstaff if you're beefy enough to swing a solid, 45lb rod. Add even a single, properly-secured weight, and it will become a mighty war hammer.
• At home — cameras (those flash bulbs are always a handy distraction), the couch, letter openers, the golf caddy, pet cages (especially if there's an animal inside), the indoor fireplace, or towels, blankets, and curtains. The flashlight at the garage is also useful both as a blinding light and as a club. Hoses are useful with or without a water stream. Also beware anyone who shouts, "Batter Up!"
• In the kitchen — knives and lots of 'em, hot pots of coffee, toasters (or you could just hit them with it), bones from meat cuts, frying pans, rolling pins, any large, solid mass of frozen food (which gives a whole new meaning to Lethal Chef), Meat Tenderizers — when applying to silverware specifically, it's Fork Fencing — a fridge door to the face, or stuffing your enemy in the freezer, the microwave (and you get bonus points for stuffing it with tin foil and oil and turning it on), a deep-fryer, a hot stovetop, china dishes, plates (break one upon the opponent's head, then use the shards as makeshift knives or throwing stars), and don't forget loaves of bread. Food can also be used as Edible Ammunition if it's hard enough and propelled at lethal speeds.
• At the office — hardback books, box cutters, letter openers, pointer sticks, laser pointers, scissors, writing implements, office electronics such as printers and fax machines, ramming someone's head through a computer screen, repeatedly smashing someone's head with the lid of a photo copier (bonus points if the machine is accidentally turned on and prints copies of the person's face pressed against the glass). Water coolers can be pushed over onto someone. Office furniture such as chairs, hot coffee, the cafeteria microwave (bonus points if this is done while that one employee's smelly food is in there.)
• In prison — Real knives are hard to get and quickly confiscated, so convicts improvise a lot. All of the above is used, with the addition of mirror glass, plastic bags, elastic bands, gum, toothbrushes, and many, many other things. Notably, ingenious inmates have been known to make usable shivs out of papier-mache toilet paper (you can literally flush the evidence), a shotgun out of iron bedposts, lead gunpowder, crafted from curtain tape and match-heads, and a firing mechanism from AA batteries and a broken light bulb. (which was used to blow out a pane of bulletproof glass before they held a guard hostage), and best of all, a fully functioning crossbow (the components included rubber gloves, a wire coat-hanger, and ten toothbrushes).
• At school — Erasers, eraser dust^note a bit less common in a post-chalkboard age, pointers, AV carts, heavy textbooks, cafeteria food, writing implements, scissors, wooden or aluminum bats or any equipment from the gym, brooms from the janitor's closet, instruments from the music classes and/or marching band, desks and chairs, and even note paper. There's also the term 'the loaded backpack' for swinging a backpack weighted with books. Let's not forget tools from automotive shop class, carpentry class, or even chemistry class if there is one (bonus points if it's thrown in the victim's eyes).
• At the store — Fresh produce, pop caps, anything in a can or glass bottle (especially soda), cash registers, depending on the store TVs, furniture, VCRs, heavy electronics, candy balls, toys. The Home and Garden and Hardware departments are veritable arsenals of melee weapons. Bee Spray makes a great alternative to mace and can shoot 15+ feet in a wide swath.
• In the wilderness — branches, fire, rocks, avalanches, bears, sharks and other local wildlife, fishing poles and hooks.
• On the off-chance you find yourself in a fully-equipped armory, but none of the actual weapons are particularly usable, you can still use them in other, more exotic ways. Modern armories full of guns will also likely have heavy ammo boxes, loose machine gun belts can make for great whips, while individual rifle rounds of larger calibers are essentially daggers or shivs. And don't forget; a grenade that can't detonate is still a several pound ball of steel, while the spoon and arming pin are more shivs.
• If you're a Damsel in Distress, always a vase. Maybe a small statue. High heeled shoes are equally good at both bludgeoning (when held) and impalement (when worn). Or a handbag (especially when preloaded with a house brick). Or a pen (we're looking at you, McAdams).
• If you have a spare stocking and a few blunt objects, you might as well Sock It to Them. A scarf, cloak or sash is equally good as a weapon in their own right, while scarves can easily double as slings, in which case any jewelry you can find will quickly become a handy projectile. They can also be used for strangulation.
• There's also the use of tools and equipment not meant for violence as weapons anyway — such as cutters, spreaders, fire extinguishers, and defibrillators.

More and more video games, especially those with Ragdoll Physics, allow the use of environmental items as a weapon. Even in early Brawlers, it was a very useful tactic. In many Platform Games, even grabbing the enemies themselves is an effective tactic.

Superheroes and Humongous Mecha have a penchant for using even larger objects, like light poles, road signs and mailboxes.

A person who uses one of these as their standard weapon may be an Improbable Weapon User. Or a Ninja. Or someone with Homemade Inventions. Improv Fu consists of using this as your main style of fight.

On a larger scale, tools and machines not intended as weaponry can be converted into such, making a Superweapon Surprise. Combat Breakdown may involve this.

Compare Improvised Armour. Also compare Martial Arts and Crafts, which is like this, only sillier, and Abnormal Ammo, where the gun is a normal weapon, but the "bullets" it shoots may be improvised. Revive Kills Zombie is a subversion where normally helpful things like White Magic, medicine, or boo-boo kisses are used offensively. Contrast with Swords to Plowshares, which is effectively the inversion of this trope.

Example:

• Films — Live-Action
• Literature
• Live-Action TV
• Tabletop Games
• Video Games
• Real Life