Survival Gametype (L4D)

This article includes basic instructions for creating a Survival mode map for Left 4 Dead.

Starting Survival

Survival rounds begin by triggering any form of panic event.
Any entity capable of telling the Director to force a Panic Event will work. Such as func_button, func_button_timed, trigger_finale, trigger_once, prop_car_alarm or even that one song on the Jukebox.
This is set up in the same method as starting a finale or crescendo event.

Navmesh

All Survival mode maps rely on using the "Finale" or "Battlefield" and the optional "Battlestation" attribute on your navigation mesh to define the play space for the Survival mode.
Setting up the Nav mesh works differently based on whether your map is exclusively for survival, or if it adds survival mode to maps already used for campaigns.

Tip:Make use of Nav_mode.cfg to more easily edit your navmesh.

Pure Survival Maps

Maps that are only meant to support survival game mode only need three nav_mesh attributes: Player_Start, Battlefield and Finale.

1. Enter Nav edit mode, select the area immediately around the player start using the Console Command nav_add_to_selected_set to pick one nav square, or nav_begin_drag_selecting followed by nav_end_drag_selecting to box select multiple squares.
2. Use the Console Command mark player_start to mark this as the player starting area.
3. Use the Console Command nav_select_radius 99999999999999 to select the entire Navmesh and mark all of it as Battlefield and NOT_CLEARABLE.
4. Use the Console Command nav_clear_selected_set to drop the entire nav mesh selection.
5. Select a few navmesh squares somewhere around the survival start trigger (or anywhere, really) and then mark those few faces as Finale.
6. Use the Console Command Nav_Save to save the navmesh.
7. Once you are sure you're done with the navmesh, perform a full analyze using nav_analyze.

Other useful attributes:

• "Battlestation" - Makes survivor bots stay close to that area when fighting.
• "Obscured" - Marks an area as being out of sight at all times. Very useful to tell the director they can freely dump infected there.
• "No_Mobs" - Forces the director to not spawn any common infected in that nav area. Good for "Arena like" maps where the CI are supposed to come through gates.

Multi-Gamemode Maps

Existing crescendo or finale events that use the "Battlefield'" or "Finale" nav attributes can often be used without any changes to the nav mesh.

If your map adds survival sections to a coop map, add a func_nav_attribute_region encasing the area you want to play Survival in, as well as areas where infected should spawn for survival.
Call it "survival_nav_battlefield" and enable the Flag "Battlefield" and "Not_Clearable". You may also add additional "func_nav_attribute_region" entities of same names for more attributes like "Battlestation", where Survivor bots tend to stay.

Note:Using both the "Player_start" and "Finale" attributes in the same area does not work in multi-mode maps.

To enable the nav attributes, you need a info_gamemode entity which force spawns a point_template entity with the output OnSurvivalPostIO.

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnSurvivalPostIO	Point_template	ForceSpawn	<none>	0.0	No

This very same point_template can be used to spawn all other entities required by survival, such as all weapons and props to block paths.

info_survivor_position

Survivors spawn at info_survivor_position entities.
Unfortunately finale maps use the same entity to "teleport" the survivors away when approaching the escape vehicle. If your survival map is also the finale of a campaign, or if your map uses the info_survivor_position for anything but the survival spawnpoint, you will need to delete those. Else your players might spawn at the wrong place.
Delete the extra info_survivor_position entities via the Info_gamemode entity, using the following outputs

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnSurvival	info_survivor_position used by finale	kill	<none>	0.0	No

Items

In L4D, all placed items in the map will spawn in survival mode regardless of the normal densities allowed in other modes. If you wish to change the item placement or numbers, you can use the info_gamemode to spawn or kill items.

In L4D2, all item spawns are removed in survival mode.
In order to spawn items, you must give every intended survival item a name. You may give all of them the same name to make it easier.

Note:Director controlled entities such as weapon_spawn and weapon_item_spawn do not work.

Add a point_template, give it a unique name which lists all survival item names in its "Template" lines.
Add a info_gamemode entity with the following outputs

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnSurvivalPostIO	Point_template	ForceSpawn	<none>	0.0	No

Warning:Using "OnSurvival" instead of "OnSurvivalPostIO" will cause ammo and ammo upgrades not to be spawned.

info_gamemode - other uses

Maps are able to load different entities, depending on which gamemode the map is run in. As mentioned in the previous section, survival gamemodes in L4D2 require a info_gamemode and point_template to spawn any items in survival gamemode at all.
The same two entities can be used to load func_brush walls, clip brushes, prop_dynamic, items, or any other sort of entity into your map for survival gamemodes. Like adding barricade props to stop players from reaching the end map saferoom.
Alternatively, you could use info_gamemode along with a logic_relay to delete items you do not wish to have in survival, like Alarm cars which when shot would start the survival round prematurely.

Mission file and testing

Before you can test your map in survival mode, you must add your map to the mission files "survival" mode section.

Note:You can better enter the map via the developer console, with the command, map [mapnamehere] survival. You still need to create a mission file before publishing the map, obviously.

Example:

"modes"
{
 	"survival"
 	{
 		"1"
 		{
 		"Map" "mymap"
 		"DisplayName" "My survival Map"
 		"Image" "maps/preview_01"	
 		}
 	}
}

The map can be loaded into survival either through the main menu, or using the console via the Command "map mapname_here survival". The latter allows you to use sv_cheats 1 while on survival mode.

Changing Default Settings via Vscript

Most, if not all, settings of survival gamemode are sets of console commands. This means that we can change how the gamemode behaves almost in its entirety.
The following Vscript can be added to any point_entity's Vscript Variable. Preferably info_director. Once the map launches, it will swap all settings with the ones you had defined.

Example:survival_horde_stage_interval_decay set to 0 will stop hordes from appearing in shorter intervals.

Note:Mutation15, Aka "Versus Survival" also removes all weapon_upgradepack_explosive on map launch.

// Survival Convars
Convars.SetValue("director_survival_setup_time",         	 0) //default:  0 	- Time limit to set up before the round auto-starts.
Convars.SetValue("survival_boomer_limit_increase",       	 0) //default:  0 	- After each special wave, increase max boomers by this amount.
Convars.SetValue("survival_charger_limit_increase",      	 0)	//default:  0	- After each special wave, increase max chargers by this amount.
Convars.SetValue("survival_horde_stage_interval",        	60) //default: 60	- Seconds between horde attacks
Convars.SetValue("survival_horde_stage_interval_decay",  	 2) //default:  2 	- After each horde attack, reduce the interval by this many seconds
Convars.SetValue("survival_hunter_limit_increase",       	 1) //default:  1 	- After each special wave, increase max hunters by this amount.
Convars.SetValue("survival_jockey_limit_increase",       	 1) //default:  1 	- After each special wave, increase max jockeys by this amount.
Convars.SetValue("survival_lull_time",                   	15) //default: 15	- Lull duration between survival waves.
Convars.SetValue("survival_lull_time_increment",         	15) //default: 15	- Increment for the lull time per wave.
Convars.SetValue("survival_lull_time_max",               	60) //default: 60	- Max lull duration.
Convars.SetValue("survival_max_boomers",                 	 2) //default:  2 	- Max boomers alive at one time.
Convars.SetValue("survival_max_chargers",                	 2) //default:  2 	- Max chargers alive at one time.
Convars.SetValue("survival_max_hunters",                 	 3) //default:  3 	- Max hunters alive at one time.
Convars.SetValue("survival_max_jockeys",                 	 2) //default:  2 	- Max jockeys alive at one time.
Convars.SetValue("survival_max_smokers",                 	 4) //default:  4 	- Max smokers alive at one time.
Convars.SetValue("survival_max_specials",                	 8) //default:  8 	- Max number of special zombies alive at one time.
Convars.SetValue("survival_max_spitters",                	 3) //default:  3 	- Max spitters alive at one time.
Convars.SetValue("survival_round_restart_delay",         	15) //default: 15	- After a loss, restart the round after this many seconds.
Convars.SetValue("survival_smoker_limit_increase",       	 1) //default:  1 	- After each special wave, increase max smokers by this amount.
Convars.SetValue("survival_special_limit_increase",      	 1) //default:  1 	- After each special wave, increase max specials by this amount.
Convars.SetValue("survival_special_spawn_interval",      	20) //default: 20	- Seconds between special spawn waves
Convars.SetValue("survival_special_spawn_interval_decay",	 1)	//default:  1 	- After each special wave, reduce the spawn interval by this many seconds
Convars.SetValue("survival_special_stage_interval",      	60) //default: 60	- After this many seconds, increase special zombie limits
Convars.SetValue("survival_spitter_limit_increase",      	 1)	//default:  1 	- After each special wave, increase max spitters by this amount.
Convars.SetValue("survival_tank_multiple_spawn_delay",   	10) //default: 10	- Delay between the two tanks during double spawns.
Convars.SetValue("survival_tank_stage_interval",         	80) //default: 80	- Seconds between tank attacks
Convars.SetValue("survival_tank_stage_interval_decay",   	20) //default: 20	- After some number of waves, reduce the interval by this many seconds


DirectorOptions <-
{
//Intentionally left blank. 
//Is required for the below Mutation15 stuff to work.
}
//Mutation15 (Versus survival) Convars. Only changed when mutation 15 is ran.
	if ( Director.GetGameMode() == "mutation15" )
	{	
		DirectorOptions.ActiveChallenge <- 1;
		DirectorOptions.cm_ProhibitBosses <- 0;
		DirectorOptions.cm_CommonLimit <- 25;
		DirectorOptions.cm_TankLimit <- 1;
		DirectorOptions.ZombieTankHealth <- 2667;
		
		// Mutation 15 Forces the start of the survival timer after 90 seconds. BUT this will only fire a "PanicEvent" output.
		// If your survival starting button also activates sounds, particles or triggers other things, those will not be triggered.
		// To make those outputs be fired, you must use the function below to automatically trigger your button.
		// Keep in mind that if your survival starting button has "ForcePanicEvent" on a timer, you'll need to include that into your calculation.
		// As an example, "SurvivalSetupTime" triggers after 90 seconds. 
		// "Survival_Start_relay" triggers after 89 seconds, but also has a one second delay for it to force the panic event. Therefore both panic events trigger at the same time.
		
		DirectorOptions.SurvivalSetupTime <- 90; //90 seconds after spawning into map to trigger panic event.	
		function OnGameEvent_round_start_post_nav(params){
		DoEntFire("Survival_Start_relay", "trigger", "", 89, null, null) //89 seconds after spawning into map to trigger this relay.
		}
	
		Convars.SetValue("director_special_initial_spawn_delay_max",	  10)   //coop default:   60   	-	mutation15 default:   10    
		Convars.SetValue("director_special_initial_spawn_delay_min",	   2)   //coop default:   30   	-	mutation15 default:    2    
		Convars.SetValue("tongue_break_from_damage_amount", 			 300)   //coop default:   50   	-	mutation15 default:  300    
		Convars.SetValue("tongue_choke_damage_amount", 					   5)   //coop default:   10   	-	mutation15 default:    5    
		Convars.SetValue("tongue_dropping_to_ground_time", 				   0.5) //coop default:    2   	-	mutation15 default:    0.5  
		Convars.SetValue("tongue_hit_delay", 							  15)   //coop default:   20   	-	mutation15 default:   15    
		Convars.SetValue("tongue_los_forgiveness_time", 				   1.5) //coop default:    1	-	mutation15 default:    1.5  
		Convars.SetValue("tongue_miss_delay", 							   3)   //coop default:   15   	-	mutation15 default:    3    
		Convars.SetValue("tongue_no_progress_choke_early_delay", 		   1.0) //coop default:    1.5 	-	mutation15 default:    1.0  
		Convars.SetValue("z_ghost_los_expected_progress", 				2000)   //coop default: 1500   	-	mutation15 default: 2000    
		Convars.SetValue("z_hunter_limit", 								   2)   //coop default:    1   	-	mutation15 default:    2    
		Convars.SetValue("z_jockey_ride_damage", 						   2)   //coop default:    4   	-	mutation15 default:    2    
		Convars.SetValue("z_jockey_ride_damage_interval", 				   0.5) //coop default:    1 	-	mutation15 default:    0.5  
		Convars.SetValue("z_max_stagger_duration", 						   0.9) //coop default:    6 	-	mutation15 default:    0.9  
		Convars.SetValue("z_pounce_damage_interrupt", 					 150)   //coop default:   50   	-	mutation15 default:  150    
		Convars.SetValue("z_pounce_stumble_radius", 					 160)   //coop default:    0   	-	mutation15 default:  160    
		Convars.SetValue("z_scrimmage_creep_delay", 					   0)	//coop default:   30   	-	mutation15 default:    0    
		Convars.SetValue("z_scrimmage_creep_rate", 						 100)   //coop default:   30   	-	mutation15 default:  100    
		Convars.SetValue("z_smoker_limit", 								   2)   //coop default:    1   	-	mutation15 default:    2    
		Convars.SetValue("z_spawn_safety_range", 						 200)   //coop default:  550   	-	mutation15 default:  200    
	}

See also

• Left 4 Dead Level Creation
• Left 4 Dead 2 Level Creation