Console commands

The console is a feature of many games that can be used to change certain elements of a game. In Left 4 Dead and Left 4 Dead 2, it can be activated in the Options menu (go to "Keyboard/Mouse", then Enable the "Allow Developer Console" option) and then displayed by pressing the tilde (~) key in game. Valve features a quick-type feature in their consoles that allows rapid entry of commands.

Note that the key used to access the developer console may be different on non-U.S. keyboard layouts; for example, a standard UK keyboard layout uses the tilde key (left of the "1" key and below Escape).

You may edit the config file within your game directory directly. The file is located under

Just open the file with a text-editor of your choice and adjust it to your needs.

Another workaround for non-U.S. keyboard layouts ― Finnish in particular ― is to switch to a U.S. keyboard layout, start the game, opening the console and typing, where x is whichever key you wish to bind the command to, then switching back to your own language. If you can't open the console by changing the keyboard layout, right click on Left 4 Dead 2 in the Steam Library, click properties, click 'Set Launch Options...' then type  in the field. Binding  to a key bypasses the Steam Cloud overwriting custom settings made, and allows you to pick a key on a familiar keyboard layout. The console key chosen might not work in the lobby or start menu, but it should work in-game.

sv_cheats
The  console variable is a prerequisite command to many of the game-altering commands found in the Left 4 Dead series (including other Valve games, such as Half-Life). In the Left 4 Dead series, by setting sv_cheats to 1, most commands are then recognized by the game. It is with  that most of the exploits were found by users in the demo during its pre-order era.

Enabling cheats disallows unlocking achievements. This includes Grind Achievements, which are achievements based on your lifetime performance (i.e. killing 5,359 Zombies in Crash Course) and any other Achievement that uses a Counter-based system to acquire (i.e. Collect 10 Boomer Bile Bombs off Dead CEDA Agents) as well, so any Infected killed with cheats enabled will not count towards Zombie Genocides or any similar achievement. Even when turned off, achievements are still disabled. Only restarting the particular game will allow achievements. Achievements can still be earned through an online game as long as cheats were never enabled on that server.

Unfortunately, enabling cheats in Left 4 Dead 2 is more complicated than in the previous game. Cheats must be enabled in the main menu, before starting a game, and even then you must use the  command to load a game with cheats enabled - starting a local server via any of the lobbies will disable cheats.

Annotated list of commands
Knowing all the commands isn't quite as good as knowing what they do. The following will describe what each command does and its default value.

Important things to know about your cheat console:
 * Some commands require you to be the game host (such as ).
 * It is assumed that you have cheats enabled for the commands described in this section.
 * If you turn on cheats then turn them off, many settings are discarded!
 * The console can auto-complete commands, making it inefficient to type more than you need to; just type a few letters and then hit the up/down arrows.
 * Commands can be chained. Example:  enable cheats, spawn a boomer, hunter, smoker, horde, then turn off cheats, all in that order.
 * You can store your commands in the " " file you create in a text editor like "Notepad" (Notepad++ is recommended for this) and put it in . While it isn't necessary to store it in the autoexec file, doing so will allow automatic execution of the commands saved when your server runs. You can also execute a particular config file, for instance, " ", by inputting " " in the console.
 * If you are not sure of the correct spelling of a command, just type the first set of letters that you know and press "Tab." A list will appear below the input field listing each command beginning with what you have just typed. Press the "Tab" key to cycle through the commands listed.

Noclip
(disables collision and physics, allows to fly through walls and in the air around the map.)

(set how fast you move when noclip is enabled)

God mode
Survivors are completely invincible.

Survivors will not take any damage, and will not be slowed by Special Infected attacks. The only real way to lose is to somehow leave everyone hanging on a ledge.

Note: If a Survivor has fallen from a ledge, or pinned somewhere out of reach, use the  command to save them.

is somewhat similar to godmode in that you cannot die, but you still receive damage. However, if you aren't the last survivor alive, you'll still be incapacitated as per normal gameplay. If you are, then whenever you take a hit that'd deplete your health, it will be reset to 10 instantly, thus protecting you from dying or incapacitatation. However, sometimes it can still kill after receiving damage rather than just incapacitation or restored HP.

Stopping the apocalypse
Using this code will stop the Director from spawning any Infected. You can explore the level without fights.

director_stop

To start the Director again, type in

director_start

Note: This code will not de-spawn any living Special Infected. Note: Infected in map design will still spawn, including the bride Witch in The Riverbank, Witches in The Sugar Mill, the Tank in train car in The Docks, as well as every Tank during the finales.

The Witch lets you come closer...a bit
z_witch_anger_rate 0.2

Setting it lower allows you to go near her without startling her as quickly.

Prop Spawner
cl_precacheinfo modelprecache This command gives you an advanced list of items. After you choose what you want, you need to place it after the following: prop_dynamic_create // creates non-movable object prop_physics_create // creates movable object

Choose your Survivor
Type up  to switch between Survivors. Entering this command while looking at another Survivor will switch to that one. If there are no Survivors directly on the crosshair, it will pick the one closest to it.

Put the name of a Survivor bot following the command to switch to that Survivor; for example,  will let you control Zoey.

Also, in online gameplay it is possible to change your designated Survivor at joining the game by opening the console and putting in: jointeam 2 It is possible also to do this when in mid-play, you just need to change your view to spectator: spectate jointeam 2

Spawn Infected
These commands can be used to spawn in additional enemies.

z_spawn tank z_spawn witch z_spawn boomer z_spawn smoker z_spawn hunter z_spawn common, z_spawn, z_spawn horde (the first two commands spawn a single common infected; the latter spawns a horde.) z_spawn mob (Mobs last a LOT longer than the usual horde)

Removing Infected
To remove Specials, use the  command, followed by the name of the special in question. For example, if a Jockey was riding you and you're a lone player, type  and it'll magically disappear. This also works on your fellow survivors - type  to see the biker dude disappear, with only his weapons and whatever other items he was carrying as the only evidence as to his existence.

This command does not work on Witches or Common Infected. To bind multiple kicks to a key, it is safer to use the  command in between the kick commands.

i.e.

bind K "kick Tank; wait; kick Boomer; wait; kick Smoker; wait; kick Hunter" This stops each command executing simultaneously, instead it waits at least one frame before parsing the next command.

Spawning more than one of the same Special Infected causes their names to go into a numbered list starting with no number. For example:


 * Hunter
 * (1)Hunter
 * (2)Hunter
 * (3)Hunter

When you try to kick a Hunter and it doesn't work, then there may be more than one Hunter on the map.

Note: For some reason, if you throw a Bile Bomb at a bunch of force-spawned Uncommons, they will start pushing rather than hitting each other, like when you bash one with your weapon. Also, if you throw a Bile Bomb on Jimmy Gibbs Jr., the Purple Aura remains on him even after the effects have faded, thus lighting him up through walls.

Counter Strike: Source weapons
Type:  in the console, and then the item names will appear.

give smg_mp5 give sniper_awp give sniper_scout give rifle_sg552 Be aware that these will do no damage whatsoever until you reload the map.

Custom Melee Weapons
These are the melee weapons that are either made by individual authors or can be found in some custom campaigns such as Suicide Blitz 2, Blood Tracks, Left 4 Evil Dead, Necropolis, Kink, Death Mountain, Deathcraft II, Redemption II, Dark Wood, Mellow Manor, Farewell Chenming, Session 9, The Bloody Moors, Fall in Death, TRAPPED, Helm's Deep Reborn, Energy Crisis, and The Scrap Yard. Some of them are either part of the maps, hidden in the map files, or can be downloaded as standalone VPKs. give aetherpickaxe give aethersword give helms_anduril give bamboo give barnacle give woodbat give daxe give bigoronsword give gloves give b_brokenbottle give bottle give chains give chair give chair2 give weapon_chalice give computer_keyboard give 2_handed_concrete give concrete1 give concrete2 give dekustick give custom_ammo_pack give dhoe give dshovel give dsword give dustpan give electric_guitar2 give electric_guitar3 give electric_guitar4 give guitar give enchsword give firetongue give fishingrod give bnc give weapon_morgenstern give b_foamfinger give fubar give gman give gaxe give ghoe give gpickaxe give gshovel give guandao give helms_hatchet give bt_sledge give combat_knife give hylianshield give iaxe give ihoe give ipickaxe give isword give katana2 give doc1 give kitchen_knife give lamp give b_legbone give legosword give lightsaber give m72law give mace give mace2 give thrower give flamethrower give mastersword give hammer give mirrorshield give weapon_sof give mop give mop2 give muffler give nailbat give sh2wood give helms_orcrist give bt_nail give lobo give pickaxe give scup give pipehammer give bow give riotshield give rockaxe give pot give weapon_shadowhand give shoe give slasher give spickaxe give sshovel give ssword give helms_sting give longsword give syringe_gun give tireiron give tonfa_riot give btorch give trashbin give vampiresword give wand give wargodblessing give helms_sword_and_shield give waterpipe give waxe give wpickaxe give wshovel give wsword give wrench give wulinmiji give arm give foot

Demo Weapons
These also work in the full game, with the exception of the grenade launcher: give autoshotgun give hunting_rifle give health give rifle give pistol give smg give shotgun give pain_pills give first_aid_kit give pipe_bomb give molotov give vomitjar give propanetank give gascan

ent_create weapon_grenade_launcher In the full game, the Grenade Launcher can be spawned via the  command as with the other weapons, but because the grenade launcher was never meant to be obtainable in the demo, it must be created using   as shown above.

Drops
Need to drop a pipe bomb or molotov instantly, damn the consequences? This will spawn an armed pipe bomb or molotov at your feet. You might want to be running when you try these.

fire // drop a Molotov in the center of the character lighting you on fire, so move fast boom // drop a Pipe Bomb in the center of the character ready to explode

How many zombies would you like?
By default, the game limits how many zombies are drawn at any given time. You can bypass this limit to get truly outrageous numbers of zombies and also make you crash.

z_common_limit 30

Now, how can we get the director to give us more mobs of zombies at random times? z_mob_spawn_min_interval_expert 90 z_mob_spawn_max_interval_expert 180 z_mob_spawn_min_size 10 z_mob_spawn_max_size 30

Still not hard enough?... Perhaps you need a mega-mob! z_mega_mob_spawn_min_interval 420 z_mega_mob_spawn_max_interval 900 z_mega_mob_size 50

All good and fine, but what about those spaced-out zombies that are just standing still, waiting for you to shoot them? Would it not be more tense if they were always moving in at you?

z_must_wander 0 z_acquire_far_range 2500 z_acquire_far_time 5 z_acquire_near_range 200 z_acquire_near_time 0.5

Okay, if you got this far, you're going to need more boss zombies. This controls time in seconds between boss spawns and the max number of bosses that can be spawned at any given time:

z_special_spawn_interval 45 z_exploding_limit 1 z_gas_limit 1 z_hunter_limit 1 z_minion_limit 3 // This limits the number of 1 type of Special Infected allowed at one time. In certain cases, you would get three Hunters; this will make sure you do not get four, so in                   places like Versus, you will not be overrun by Smokers / Hunters / Boomers.

That's still not enough zombies? Well, then, time to panic (A.K.A., mega-mob on demand)!

director_force_panic_event

Still alive there? Try this one:

director_panic_forever 1

But if you like beating the crap out of every single one, try this as well:

STEP 1: z_common_limit 400

z_special_spawn_interval 45 z_exploding_limit 1 z_gas_limit 1 z_hunter_limit 1 z_minion_limit 9 z_spawn mob z_spawn tank // you WILL be overrun with lots of Infected if you try this

Note: Of course, spawning too many zombies at the same time can slow down your computer or even crash it (or your game).

No more rescues
Don't like the fact that dead isn't dead? Fix it! The variable " " controls how far your teammates must get beyond your dead corpse before you can be rescued. Set to minus one to preclude that ever happening. The second variable, " ", controls how many seconds must elapse after death before you come up for reincarnation. Set to "-1" to preclude that possibility.

rescue_distance 4500 rescue_min_dead_time 60

Bite me
What if Infected could kill you with one bite?

hunter_pz_claw_dmg 10 z_pounce_damage 5 // There's a delay of 1 second where a teammate can knock it off and you don't take this damage tongue_choke_damage_amount 10 z_hit_from_behind_factor 0.5 // If a zombie hits you in the back, multiplies the damage done z_witch_damage 100

Environmental and unknown damage modifiers:

inferno_damage 40 // Damage per second when getting flamed survivor_extra_damage_ammo_factor 1.25 // Appears to multiply the overall amount of                                           friendly fire damage. At zero, it does no                                          damage, even on expert though a decimal with many places will still do a good chunk with the Auto Shotgun. Does not appear to change damage on Infected at all. TODO: test this more z_gun_damage 10 // Melee damage done to doors, boxes, and the like, but not Infected

Walk or sprint?
Don't like the fact that you have a walk key instead of a sprint key? Set this variable to something ludicrous like 5,000...

survivor_walk_speed 85 // For reference base, movement speed is 210 and base Infected speed is 250

Still not fast enough? Use the following to get in and out of the action at faster than light speeds. REQUIRED: you must be the game host

warp_all_survivors_here  // Warp all survivors to the player's cursor warp_all_survivors_to_battlefield // Warp all Survivors to the battlefield warp_all_survivors_to_checkpoint // Warp all Survivors to the exit checkpoint warp_all_survivors_to_finale // Warp all Survivors to the finale radio warp_far_survivor_here // Teleport the farthest away Survivor to your cursor position warp_to_start_area // Warp yourself to a Survivor spawn area

Versus Mode for the Man With No Friends
Well, maybe "no friends" is a bit drastic, but this will help you when you need some Versus and have no one to play with.

sv_cheats 1 sb_all_bot_team 1 sb_unstick 0 // stops bots teleporting vs_max_team_switches 99 chooseteam // or use "M" or whatever key you have assigned to team change mp_gamemode versus

Do note that the Survivor Bots will walk through the stage well enough, but may get hung up when it comes to pushing certain buttons or leaving certain areas. Simply switch teams again, accomplish the goal, and switch back. Do take note that the map that you are playing is still a co-op map and may end prematurely once both teams have played through. To avoid this, vote for a change in campaigns to load the Versus version of the maps.

NOTE: This cheat has been patched. In order to do this, you must enter. You must then finish the level and you will switch teams afterwards. If you want the AI to play with you, enter. The AI will then spawn other Infected to play with you. They won't make the best decisions, and you will likely be the only one killing anyone. You can also play survival mode by entering. You cannot use this method for Left 4 Dead 2, as mp_gamemode is not recognized by the Developer Console. You must enter. For example, to play Versus Mode on The Hotel, you must enter "map c1m1_hotel Versus". This will allow you to play Versus for the entire campaign. The  command is also not recognized, so you must enter "vs_maxteamswitches" and then set it to something big like 999. Often, you will spawn in on the second or third map as the wrong team, so you can still switch. Sometimes, you will even spawn in as a Spectator. You will have all AI teammates, unlike the first Left 4 Dead where playing Versus by yourself meant by yourself.

NOTE: The Survivor Bots won't leave the safe room unless you enter "sb_all_bot_team 1". They will move through the level very fast, but they won't sit in the safe room for hours.

NOTE: With the release of The Sacrifice, the  command is no longer recognized in Left 4 Dead 2, and has been renamed to , which will only work with the command line option. This is not a console command. This can be added by right-clicking on the game in Steam, selecting "properties," clicking "Set launch options," and adding it there.

NOTE: If all of those don't work, try this:

sv_cheats 1

sb_all_bot_team 1 sb_all_bot_game 1 If that doesn't work: director_no_human_zombies 0

director_force_versus_start

Then hit the team change key (M by default). You can choose if you like to be an Infected or Survivor.

Survival mode
Playing Survival mode on single player is simple enough; it doesn't even require cheats. map (map) Survival

LAN game
To play offline on a local LAN (works with Steam in offline mode and you only need one Steam account) sv_lan 1 sv_allow_lobby_connect_only 0 map Then without hitting enter after "map", you will see a list of available maps. typing the first letter of the map name will give you more choices. connect IP_ADDRESS
 * 1) Set launch option -console
 * 2) Launch the game on server and clients
 * 3) On the server, bring up the console (~) and type:
 * 1) Wait for the game to start
 * 2) Vote for the difficulty level you want.
 * 3) Input   to check the IP
 * 4) On the clients, bring up the console and type the following, replacing IP_ADDRESS with the servers LAN IP address:

Bile/Rock Target Practice
Let's face it―you know it, your parents know it, your dog knows it: Puking and throwing is hard as hell to master. These are a few simple commands you can use 5 minutes a day 3 times a week that will make you a sexy puking/throwing master, you know, just like those workout ads.

Basic sv_cheats 1 // You'll need this for all the commands map l4d_airport03_garage Versus // This level provides an extremly good practice environment, but you should try other maps, too sb_all_bot team 1 // Without this, the game will shut down because there aren't players on the other team sb_stop 1 // Without this, the Survivors will get in the way of your game; best to put this cheat in before sb_all_bot_game 1 Rock throw practice z_spawn tank z_tank_rock_debug 1 // Creates a small cube where your rock hits, helps get an idea of where your throws land z_tank_throw_interval 1 // Makes the delay between throws nonexistent; just dont get used to throwing rocks like a submachine gun z_spawn boomer // These provide excellent target practice Bile practice z_spawn boomer z_vomit_debug 1 // Similar to z_tank_rock_debug 1, only it creates lines to show where the puke hitboxes travel. In other words, shows where you barf) z_vomit_interval 1 // What progress do you expect to make only                     puking every half-minute? Now you can do                      it every second. Again, don't get used to                      puking like a submachine gun

Pitch Black Mode
Disable the white background fog to play the game without the unrealistic lighting effect. This was the original way the game was designed per the development team: Left 4 Dead takes place in a variety of dimly lit night-time environments. Because of this, play testers weren't able to see zombie silhouettes in the mid-ground and background. Because of this, they were repeatedly getting mobbed. While sudden zombie attacks were unarguably scary, they were also frustrating—players weren't being given the information they needed to react. They wanted that "Here they come!" moment, and we weren't giving it to them. The solution? Light-colored fog. While not as realistic-looking as actual fog in some settings, it meant play testers could see attackers in the distance. Once they were able to anticipate attacks, play testers started to have a much better time." sv_cheats 1 fog_override 1 fog_enable 0

But remember to wisely use it in L4D2 – disabling fog somehow also disables rendering of water, leaving empty spaces everywhere where there used to be wet - not recommended for Swamp Fever and Hard Rain!

Full-Lit Mode (On by default if the map doesn't have any entities for lighting)
If you wish to explore the map in full daylight mode use:

No-texture Mode
Want something else to see? Try using  for size! No models in-game will be textured, that's not counting the eyes of your Survivor fellows.

Flashlight
Alternatively, if you wish to use your flashlight to see the difference between daylight and normal map lighting, use the following commands: r_flashlightconstant 1 // select constant attenuation instead of linear or quadratic light fall off. r_flashlightfov 179 // default is 53 degree cone. r_flashlightfar 9999

Taking screenshots
To hide crosshair and other overlay elements: sv_cheats 1 hidehud 4 0 returns to normal. 2 and 3 toggle certain elements on/off. Even though it does not look like you can change weapons, cl_drawhud 0 might help you more.

Change Player Name
This allows a player to use a name different from their Steam name. setinfo name example

This allows the name change to be bound to a key as well. Additionally, this is temporary and only lasts on the game you are on until it's finished or you leave. To use names that have spaces in them, surround the whole thing in quotes, so if you wanted Example Name as your temporary name, you would type:

setinfo name "Example Name"

Kill
Do you want to end your cruel life? Just type " " in the console and you will die instantly. Is there a player that's being a pain? Then type " ". But it has to match the player's/NPC's name's case; so, to kill Bill, type " ". A side note is that you do not need to type the whole name; to kill Louis, for instance, you can simply type " " and your work is done. This won't work if someone else has L at the beginning of their name, so just keep going until the name string is unique.


 * Note: The following only applies in Left 4 Dead 1: Using this code on Boomers will neither cover Survivors around him/her in Bile nor stumble anyone standing too close.

" " works too.

Respawn
Enter " " if you want to live again.

Additionally, you can type "respawn_all" to ressurect bots and other dead players.

Third-person
Tired of first-person view? Want to get a better look at that scratch on the back of Bill's shirt? Type in " " or if you like it like Gears of War/Resident Evil/Mass Effect, type in " " to get a view from your shoulder.

firstperson thirdperson thirdpersonshoulder Note: By default, the crosshair in third person mode isn't aligned properly, so all of your shots will go either left or right of the cursor, depending on the distance. The following code will solve this;

c_thirdpersonshoulderoffset 0 c_thirdpersonshoulderaimdist 720 c_thirdpersonshoulderdist 40 c_thirdpersonshoulderheight 20 cam_ideallag 0

Ignite yourself
The command  gives you the fire overlay below your screen and the ability to light movables by just jumping on them. Best used in combo with a Hunter as it gives you the extra damage. This command does no self-damage.

People Start Talking
Type " " to have your character speak. Most people have been observed as (over)using " ". Nearly all of the commands for this command start with " " An update on February 19th, 2010 has disabled this command for Left 4 Dead 2, but this is still available in the original. This does not require the use of "sv_cheats 1". Some players have made their own radial voice menus (x and z key commands) as an add-on in order to still have that feature in Left 4 Dead 2.

No Special Infected
Enter:. In finales, there might still be certain Specials that will still spawn however, you can get rid of them by kicking them out. For example, "kick tank" or "kick hunter," you can bind the kick command to a key so when they show up, press the key you bound it to and they will disappear, out of sight, out of mind.

Infinite Ammo
To have infinite grenades, ammo, or chainsaw fuel, just type in console. Or if you just want it for your primary weapon, type

Items
To visually see all items that spawned (yellow), and that could possibly spawn in the map (white), use

director_debug_scavenge_items 1

General AI status
To see the general status of the AI Manager (Director), use:

director_debug 1

Left 4 Dead 2 Commands
To activate cheats within Left 4 Dead 2 start a map using the  command. Achievements will be turned off, however. Most commands from Left 4 Dead work in Left 4 Dead 2, but some have been removed: team_desired survivors_walk_speed If you use the command z_spawn mob in Left 4 Dead 2, some of the Uncommon Infected that appear in that level will be mixed in with the regular Common Infected. The new weapons in Left 4 Dead 2 can be acquired using the following commands.

As all of the original Left 4 Dead weapons appear in Left 4 Dead 2, you can spawn all of them (except for the M1911 Pistol, which got replaced with P220s and Glocks!)

NOTE: Some melee weapons can only be spawned in certain campaigns. For instance, Crowbars cannot be spawned in "Swamp Fever" unless you edit the text files in your games directory to be able to do so. give weapon_grenade_launcher // some people may have to rely on ent_create weapon_grenade_launcher give rifle_desert // Gives the Combat Rifle give rifle_ak47 give pistol_magnum give shotgun_chrome give shotgun_spas give sniper_military give smg_silenced give vomitjar // Bile bomb give defibrillator give electric_guitar give machete give frying_pan give katana give rifle_m60

You can also use the console to give your weapon any of the three upgrades in Left 4 Dead 2. upgrade_add LASER_SIGHT upgrade_add explosive_ammo upgrade_add INCENDIARY_AMMO

The explosive ammo can be modified with the following commands. Setting one of the force commands too high will result in the game crashing. upgrade_explosive_bullet_force // explosive force for all weapons other than shotguns upgrade_explosive_slug_force // explosive force for shotguns upgrade_show_explosive_ammo_radius // changing to 1 causes a sphere to be shown whenever an explosive shot is fired, showing its area of effect

The Special Infected new to Left 4 Dead 2 can also be spawned: z_spawn spitter z_spawn jockey z_spawn charger

Playing any Mutation
The following commands will allow you to play any of the revealed Mutations with bots. map mutation# //Replace # with a number: mutation1 = Last Man On Earth mutation2 = Headshot! mutation3 = Bleed Out mutation4 = Hard Eight mutation5 = Four Swordsmen mutation6 = Nothing mutation7 = Chainsaw Massacre mutation8 = Iron Man mutation9 = Last Gnome On Earth mutation10 = Room For One mutation11 = Healthpackalypse! mutation12 = Realism Versus mutation13 = Follow the Liter mutation14 = Gib Fest mutation15 = Versus Survival mutation16 = Hunting Party mutation17 = Lone Gunman mutation18 = Bleed Out Versus mutation19 = Taaannnkk! mutation20 = Healing Gnome community1 = Special Delivery community2 = Flu Season community3 = Riding My Survivor community4 = Nightmare community5 = Death Door community6 = Confogl It is recommended that  is set to 1 if playing a competitive Mutation alone as the game will disconnect due to lack of players.

Realism mode
Like with Survival mode, playing a single-player Realism mode in Left 4 Dead 2 is as follows: map (map) realism

Force Uncommon Zombies
Type z_forcezombiemodelname common_male_(Infected);z_forcezombiemodel 1;z_spawn

Replace (Infected) with the names below: ceda = Hazmat CEDA zombies from Dead Center. jimmy = Jimmy Gibbs zombie from Dead Center's last level. fallen_survivor = The Fallen Survivor from The Passing. clown = Clowns from Dark Carnival. mud = Mud-Men from Swamp Fever. riot = Riot Cops from The Parish. worker = Workers from Hard Rain.

If you use the Fallen Survivor, you might want to use these:

z_fallen_kill_supress_time 1 z_fallen_max_count 30

Complete list of commands
See: Complete list of console commands

Also, don't forget "bind"; use this to make madness such as:  With this, every time you press "G," you will spawn a Tank. However, keep in mind that the default limit of Special Infected is four (not counting Tanks or Witches), so if there are already four Special Infected spawned by the Director, you cannot spawn more. The Director-spawned Infected must be killed before more can be spawned.

Bots copy your actions
Like the effect of Follow the Leader? Then you could manipulate the actions your CPU-controlled allies and the CPU-controlled Special Infected (Special Infected who are playable in Versus Mode). Every movement you make will be followed by these bots, thus negating their A.I. functionality. These are all applied with the console command The command is quite self explanatory - every movement you make affects the movement of the bots, you shoot, the bots shoot (in the case of Special Infected, using their Special abilities is the equivalent of shooting), you walk forward, they also walk forward. This is a strategy if you want to direct the actions of the bots around you. Such as when you are ridden by a Jockey, this console command allows you to control both your player and the Jockey itself!
 * When this command is enabled, the human player cannot use items, pick up weapons, etc (deactivating the Use key), it is up to him to direct the bots to the items, since they can do it instead.