Team Fortress Classic

Team Fortress Classic is a 1999 multiplayer computer game by Valve Software. It's an official port of the original Quake mod, released to ease the wait between it and Team Fortress 2, its soon-to-be-released sequel (which, considering Valve Time, naturally was released eight years later), and is often packaged with Half Life.

Unlike its cartoonier sequel, Team Fortress Classic had no backstory at all. Two teams, Red and Blue, either try to steal each others' flags, assassinate a scared-looking fellow, or impede their progress through a desert or Italian town. No corporation civil wars, no Multinational Team of misfits ... just nails and grenades.

Tropes exemplified:

 * Back Stab: The Spy's knife is an instant kill, but only if you hit the opponent in the back.
 * The Big Guy: The Heavy Weapons Guy (HW Guy). Even though he's the same height as the other models, he's visibly ripped as much as 90s graphics will allow.
 * BFG: HW's Minigun, the Medic's Super Nailgun, and the Soldier's Rocket Launcher and Pyro's Napalm Cannon.
 * Butt Monkey/Chew Toy: The Civilian. Wields a short range umbrella for a weapon, moves slowly, and has very little health. Often was ridiculed in the fanbase.
 * Caltrops: Part of the Scout's arsenal, cuts movement in half and does continual damage, akin to being set on fire or poisoned.
 * Charged Attack: The Sniper Rifle does this. Hold it down long enough, and a simple body shot will suffice to One-Hit Kill targets. Of course, Snipers who do this get labeled "noob bodyshotters" by "Stop Having Fun!" Guys, just as in TF2.
 * Combat Medic: Far more so than his distant German cousin. The Medic, while not able to heal from a distance, had a shotgun, a BFG Nailgun far, far superior to its normal counterpart, mobility comparable to that of the Scout's (including the ability to conc-jump), and worst of all, the ability to hit enemies with an infection attack. It's like being on fire, except there's higher DPS, it spreads to your teammates, and it can never, ever be put out, except by an allied Medic. (Or death.) There was even a popular binded message for this: "Infected? Go to Resupply and tell your friends!".
 * Dronejam: You can accidentally (or not) get in the way of your own allies.
 * Escort Mission: Protecting the Civilian.
 * Notably, one of you actually has to play as the Civilian, a tenth class that is armed with nothing but an umbrella and has really low health.
 * Fragile Speedster: The Scout. Compared to his bat-swingin' Bostonian brother, his nailgun is super-accurate, but weak, and the projectiles take time to hit their target (the target can even Dodge The Bullets), and his single barrel shotgun makes the scattergun look like a Redeemer. Instead, he's much faster (even more so than aforementioned brother) and can use concussion grenades to hop like a flea all over the place. Oh, and leave caltrops to slow down the movement of pursuing enemies.
 * Friendly Fireproof: Depends on the server.
 * Gas Mask Mooks: The Pyro and Medic - or, at least, the Medic's updated model (the old one wore a surgical mask).
 * Heroic Mime: Except for "MEDIC" or "EXCUSE ME! I AM IN NEED OF MEDICAL ATTENTION!", the characters are mostly silent.
 * Homage: The very popular level "Rock2" was based on the movie The Rock. The bases were prisons, and capturing the "flag" involved taking the gas to a dispersal room and setting it off (then frantically running to a safe room before poison gas killed everyone on the map.
 * Kill It with Fire: The Pyro, who has a bit more fire to play with compared to his Team Fortress 2 counterpart. The flamethrower behaves differently than Team Fortress 2 flamethrowers, as the fire blast doesn't "turn" as fast, and is weaker than its notoriously weak cousin. The Napalm Cannon, on the other hand, is a more damaging, AoE-based Flare Gun/Rocket Launcher combo that has more ammo than the rocket launcher or the flare gun, but its projectiles and reload time are far slower.
 * Infinite Flashlight: Still in the code. Can be utilized by hitting the ~ key and typing: bind "impulse 100"
 * Laser Sight: Sniper Rifle uses this, in place of crosshairs. Comes in the form of Crosshair Aware--if one dances over your vision, you will explode into a pile of giblets, unless you move. Fast. Just like in Team Fortress 2, the laser itself is invisible--all that can be seen is the dot of light on walls, or unfortunate teammates.
 * Ludicrous Gibs: Some server mods change it so that not only are all the gibs skulls, but you explode into a shower of them upon the slightest provocation when dying.
 * Made of Explodium: The Heavy and Demoman have a MIRV grenade. It's a grenade that first causes a massive explosion, then splits into normal grenades.
 * Oh Crap: The Civilian's only facial expression. Entirely justified by his situation.
 * Percussive Maintenance: The Engineer fixes and upgrades his equipment by smashing it repeatedly with his wrench.
 * Playing Possum: One of the spy's abilities.
 * Ranged Emergency Weapon: The Engineer's railgun. Terrible damage output and rate of fire, but it has a unique ammo supply.
 * Recursive Ammo: The MIRV grenade again.
 * Red Eyes, Take Warning: The pyro's visor is red, regardless of team color. Shortly following seeing it, you are set on fire.
 * Shout-Out: Capturing the enemy's flag results in a Scare Chord from Star Wars.
 * Sniper Duel: a major problem with people who play Sniper is that they start focusing on gibbing each other to the exclusion of all else--such as, say, winning the mission. This can be exacerbated by bog-standard level design (looking at you, 2Fort) with only one place for Snipers to even hang out. In the end, a lot of servers just limited how many people could play Sniper at one time.
 * Except for servers who hosted exclusive Sniper Duel maps.