Water
Running. The player can hold down the 'run' key to double the speed.
Jumping. The player can tap the 'jump' key to jump. The player jumps further if moving forward, and jumps higher if moving up a slope at the time.
Swimming. When underwater, the player can aim in the direction he/she wishes to go, and move forward. The player has full three-dimensional freedom. The 'jump' key is used to move straight up towards the surface. Once on the surface, the player can tread water by holding down the 'jump' key.
Shooting. The player can tap the 'shoot' key to fire. The player can hold it down to keep firing.
Using objects. There's no special key to use objects. The player can push a button or open a door, by walking up to it. To ride a platform, the player can step on top of it. If a door won't open or a platform won't lower, the player might need to do something special to activate it.
Picking up stuff. To pick up items, weapons, and powerups, the player has to walk over them. When an item isn't picked up this means the player already has the maximum possible of it or the item is inferior to what the player already has.
The physics in Quake are like in reality. However the amount of gravity can vary from level to level.
Safe enough unless the player stays under so long he/she starts to drown. The player has to come up for air periodically to prevent this. In water a player moves slower than by walking or running.
Hurts the player instantly and keeps on hurting. The player should stay out of slime unless the player has a biosuit.
The player should keep out of lava because it's extremely deadly.
Explosions 
Radioactive containers
Radioactive containers are in some military bases. Shooting these things unleashes a big explosion. The player should be careful and may not want to stand too close in a firefight. Grenades and rockets cause explosions too, of course the blast can hurt the player if too close. Besides that explosions will hurt when too near, the player will also be blown away.
Trap
Quake has many different traps. Traps can't be classified because they come in many varieties, monsters in ambush, spike shooters, crushing walls, trapdoors, etc.
Secret
Secrets are hidden lots of ways. The player might need to shoot a button, kill a monster, walk through a secret motion detector, etc. All secrets in Quake are indicated by clues. An angled texture, a light shining under a wall, a strange sound anything might be the clue. Something prominent in a room might be decoration or it might be the clue.
Button
Buttons are activated with a touch.
Shootable button
Some buttons can't be triggered by touching them. These buttons are most often in a spot the player can't reach. The player should shoot at these buttons to activate them.
Floorplate
Floorplates are activated by stepping on them.
Most doors open at the players approach. If one doesn't, the player should activate a button, floorplate, or have a key to open the door. Some doors are camouflaged and open secret areas. Almost all secret doors open when they are shot or hit with an axe. The rest are opened by hidden pressure plates or buttons.
Some secret doors have to be triggered by hidden buttons or floorplates. Others open when the player shoots them. These secret doors mostly have a distinctive looking texture.
Elevators go up and down. When the player steps on top of a elevator, it rises to its full height, and usually only lowers when the player steps off. Some elevators first have to be lowered via a button or pressure plate before they can be used by stepping on top of them.
The lifts always have to be activated by a button or pressure plate. Depending on the initial state the lift goes up or down when activated. The lift moves back to the original position after some time.
Platforms follow tracks around rooms or levels. Some have to be activated by buttons or pressure plates, others move around constantly.
Bridges are activated by buttons or pressure plates. Some bridges will stay in the extended position after being activated. Others will return to there initial position after some time.
These are distinctive in appearance and emit a unique sound. A player stepping into a teleporter, is instantly transported to another teleporter, or on top of a teleport pad. If the player is teleported directly on top of somebody else, he or she is killed instantly.
These tunnels will transport the player to other areas. Usually the player can jump up into the tunnel and will be pushed to another place by the wind.
Axe
This weapon is a players last resort. Every player will always have this weapon. It's only useful at very close range but at least this weapon doesn't use any ammo. A player can perform a maximum of 2 swings per second with the axe. One hit with the axe does a damage of 20 hit points.
Shotgun
This is one of the basic weapons a player will always have. The shotgun uses one shell per shot. Firing the shotgun gives an instant hit. The shotgun has a maximum fire rate of 2 shots per seconds. Firing with the shotgun frees 6 bullets each applying a damage of 4 hit points.
Double-barreled Shotgun
This weapon uses two shells per blast. It's more useful at close range because its shot pattern is very loose at long range. The reloading of this weapon takes some time and this weapon also gives an instant hit. The super shotgun has a maximum fire rate of 10 shots per 7 seconds. Firing the double-barreled shotgun frees 14 bullets each applying a damage of 4 hit points.
Nailgun
Two barreled gun that shoots nails. The nails are fired at a high rate but are moving slow compared to for instance the bullets of a shotgun. The nailgun shoots nails at a rate of 10 per seconds. Each nail applies a damage of 9 hit points.
Super Nailgun
Gun with four cyclic barrels that fires spikes. The spikes do more damage than the nails fired by the nailgun. The fire rate is also 10 spikes per second and the spikes are moving at the same speed as the nails of the nailgun. Every spike uses two nails ammo and applies a damage of 18 hit points.
Grenade Launcher
This weapon fires grenades which bounce off the wall or floor. When a grenade hits someone, it explodes. If it misses, the bomb sits on the floor for a moment, then explodes. The grenade launcher uses rockets as ammo. This weapon can launch at most 10 grenades per 6 seconds.
Rocket Launcher
This weapon fires rockets that will explode as soon as they hit something. It's preferred to use this weapon at mid to far range because the rocket impact will also damage the gunner when used at close range. It is possible to fire up to 10 rockets per 8 seconds.
Thunderbolt
With this weapon the player is able to fire a constant lightning at the enemy to deliver a tremendous amount of damage. This weapon is often called the lightning gun for an obvious reason. The thunderbolt uses cells as ammo and uses them at a rate of 10 cells per second. A hit lasting a second with the thunderbolt applies a damage of 300 hit points. Firing the thunderbolt in water, slime or lava will result in an explosion damaging everyone in a certain radius.
Shells
For shotgun and double-barreled shotgun. A small box holds 20.
Nails
For nailgun and super nailgun. A small box holds 25.
Rockets
For grenade launcher and rocket launcher. A small crate holds 5.
Cells
For the Thunderbolt. A small battery has 6 charges.
Adds to the players health up to 100 percent. It comes in packages of 15 and 20 percent.
Armor
Comes in three flavors; green, yellow, and red, from weakest to most powerful. Better armor gives more protection against weapon hits of enemies.
Megahealth
Gives the player 100 additional hit points. After a few seconds, all hit points over 100 start to drain away slowly.
Gives the player the ability to breathe underwater and swim through slime without harm. Does not protect against lava.
Ring
of Shadows
Renders the player almost totally invisible. Only the player's eyes can be seen.
Pentagram
of Protection
Renders the player invulnerable.
Quad
Damage
After picking up this powerup the weapon used by the player delivers four times the damage.
Double-barreled
Shotgun
Gives the player the doube-barreled shotgun and 15 additional shells.
Nailgun
Gives the player the nailgun and 30 additional flechettes.
Super
Nailgun
Gives the player the super nailgun and 30 additional flechettes.
Grenade
Launcher
Gives the player the grenade launcher and 5 additional rockets.
Rocket
Launcher
Gives the player the rocket launcher and 5 additional rockets.
Thunderbolt
Gives the player the thunderbolt and 15
additional cells.
gold and silver key
gold
and silver key card
gold and silver rune key
Dimension
of the Doomed
Realm of Black Magic
Netherworld
The
Elder World
Slime
Lava
Door
Secret Door
Elevator
Lift
Platform
Bridge
Teleporter
Wind tunnels
Health
Biosuit