From Valve Developer Community
npc_citizen is a point entity available in the Half-Life 2 series.City 17. They will pick up weapons, fight the Combine, and join the player's squad if they see him.
Note:Some keyvalues, flags, inputs, or outputs might not affect an NPC, based on the functionality and coding of the NPC.
Dedicated Console Variables
- ai_citizen_debug_commander <bool>
- When a citizen is selected with
ent_text, provides additional information about how the citizen processes commands from the player.
- g_ai_citizen_show_enemy <bool>
- When a citizen is selected with
ent_text[confirm], draws a line from the citizen's eyes to the eyes of its enemy during combat.
- npc_citizen_auto_player_squad <bool>
- Makes the citizens automatically join the player's squad as long as there within a minimum distance to the player and a squad slot is available.
- npc_citizen_auto_player_squad_allow_use <bool>
- If set to 1, makes the citizens join/unjoin the player's squad when they +USE the citizen, as long as a squad slot is available.
- npc_citizen_explosive_resist <bool>
- Resistance against exposions.
- npc_citizen_insignia <bool>
chefhat.mdlon the heads of citizens in the player's squad.
- npc_citizen_squad_marker <bool>
- Adds a small marker under their feet when the citizens are in the player's squad.
- sk_citizen_giveammo_player_delay <float>
- Time between ammo assistances.
- sk_citizen_heal_ally <int>
- Amount of health to heal allies for.
- sk_citizen_heal_ally_delay <float>
- Time between medical assistances for allies.
- sk_citizen_heal_player <int>
- Amount of health to heal players for.
- sk_citizen_heal_player_delay <float>
- Time between medical assistances.
- sk_citizen_heal_player_min_forced <int>
- Players must be at least this far from their max health before medics can heal them again.
- sk_citizen_heal_player_min_pct <float>
- How much health a NPC has to have before medics will consider healing them. Target's health * this variable.
- sk_citizen_health <int>
- A citizen's spawn health.
- sk_citizen_player_stare_dist <float>
- How far medics have to be from the player to register healing requests from staring.
- sk_citizen_player_stare_time <float>
- How long a player has to stare at a medic before they give them health.
- sk_citizen_stare_heal_time <float>
- How long to wait after healing someone before medics can resume stare healing request behavior.
- Weapon to spawn with.
- Ammo To Resupply
- If the appropriate spawnflag is set, the citizen will attempt to get close to the player and pass this type of ammunition when he/she runs low.
- Amount Of Ammo To Give
- Amount of ammo the NPC has (in total) to give to the player.
- Changes the citizen's appearance (but not behaviour).
- Default: The hardcoded default for the given chapter. All custom maps use Downtrodden.
- Downtrodden: The normal blue civil outfit.
- Refugee: A more ragged and torn civil outfit. Some models use a beige shirt.
- Rebel: The rebel outfit.
- Unique: Only uses what is stored in the "model" keyvalue. This can be used if you want to use a different model from other citizens, like Odessa Cubbage. Warning:Make sure the
Random Headspawnflag is off when using Unique citizens
- Expression Type
- Ambient facial animation.
Literal Value Description 0 Random 1 Scared 2 Normal 3 Angry
- Various model overrides. With the
Random Headspawnflag, any of these models except for Cheaple and Odessa may be chosen.
Cheaple Male 1is a low-detail model that only works if Type is Downtrodden or Unique.
Odessa. DO NOT USE.is Colonel Cubbage. Only works if Type is set to Unique.
- This field accepts arbitrary paths (e.g.
models\alyx.mdl). Use the Unique citizen type if you want to make use of this.
- Expression Override
- Facial expression override
- Fire Output When Nav Is Blocked?
- Fires an output when the Citizen's movement fails because he/she is blocked by a dynamic object.
- Permanent Squad Member?
- A permanent squad member cannot leave the player's squad unless killed or explicitly removed by entity I/O. Only use this if you're sure you want to override the default AI.
- Deny Command Speech Concept
- If you want your citizens to squad with the player but not obey commands the player gives to move the squad, put a concept here and this citizen will speak the concept instead of obeying the order.
- Always transition
- This NPC will always teleport to a Player Squad Transition Point if they're not within the trigger_transition.
- Prevent picking up weapons?
- This NPC will NOT be allowed to pick up weapons they find on the ground.
- Is this a vital ally?
- This NPC will cause the game to end if killed.
- Use Sentence
- Sentence spoken when the NPC gets used by a player
- Un-Use Sentence
- Sentence spoken NPC gets used again
- Don't Use Speech Semaphore
- Friendly NPCs are not allowed to speak if another friendly NPC is speaking. In some cases we don't want speaking NPCs to prevent other NPCs from speaking (for instance, if there is a friendly NPC speaking for a long time on a monitor). To make this NPC not prevent other NPCs from talking, make it not grab the semaphore when it speaks.
- Values for
- Target Path Corner
- The path_corner that this NPC will move to after spawning.
- Squad Name
- NPCs that are in the same squad (i.e. have matching squad names) will share information about enemies, and will take turns attacking and covering each other.
- Hint Group
- Hint groups are used by NPCs to restrict their hint-node searching to a subset of the map's hint nodes. Only hint nodes with matching hint group names will be considered by this NPC.
- Hint Limit Nav
- Limits NPC to using specified hint group for navigation requests, but does not limit local navigation.
- Sleep State
- Holds the NPC in stasis until specified condition. See also 'Wake Radius' and 'Wake Squad'.
- 0: None
- 1: Waiting for threat
- 2: Waiting for PVS
- 3: Waiting for input, ignore PVS
- 4: Auto PVS
- 5: Auto PVS after PVS
- Wake Radius
- Auto-wake if player within this distance
- Wake Squad
- Wake all of the NPCs squadmates if the NPC is woken
- Enemy Filter
- Filter entity to test targets against
- Ignore unseen enemies
- Prefer visible enemies, regardless of distance or relationship priority
- Physics Impact Damage Scale
- Scales damage energy when this character is hit by a physics object. With a value of 0 the NPC will take no damage from physics.
- Disable shadows
- Prevent the entity from creating cheap render-to-texture shadows. Does not affect shadow mapping.
- Disable ShadowDepth
<boolean>(New with Portal 2)
- Used to disable rendering into shadow depth (for projected textures) for this entity.
- Projected Texture Cache
<choices>(New with Portal 2)
- Used to hint projected texture system whether it is sufficient to cache shadow volume of this entity or to force render it every frame instead.
- 0 : Default
- 1 : No cache - render every frame
- 2 : Cache it - render only once
- Render Mode
- Set a non-standard rendering mode on this entity. See Render Modes for details.
- FX Amount (0 - 255)
- Intensity of the selected render mode.
- FX Color (R G B)
- Color used by the selected render mode (if applicable).
- Disable Receiving Shadows
- Prevents the entity from receiving shadows.
- Render FX
- Several GoldSrc-era visibility modes which change the way the entity is rendered, typically by fading it in and out.
- Pitch Yaw Roll (Y Z X)
- This entity's orientation in the world. Pitch is rotation around the Y axis, yaw is the rotation around the Z axis, roll is the rotation around the X axis.
- Entity Scripts
<scriptlist>(New with Left 4 Dead 2)
- Space delimited list of VScript files (without file extension) that are executed after all entities have spawned. The scripts are all executed in the same script scope, later ones overwriting any identical variables and functions.
- Script think function
<string>(New with Left 4 Dead 2)
- Name of a function in this entity's script which will be called automatically every 100 milliseconds (ten times a second) for the duration of the script. It can be used to create timers or to simulate autonomous behavior. The return value (if present) will set the time until the next call. Note:Try to avoid expensive operations in this function, as it may cause performance problems.
- 1 : Wait Till Seen
- 2 : Gag (No IDLE sounds until angry)
- 4 : Fall to ground (unchecked means *teleport* to ground)
- 8 : Drop Healthkit
- 16 : Efficient - Don't acquire enemies or avoid obstacles
- 128 : Wait For Script
- 256 : Long Visibility/Shoot
- 512 : Fade Corpse
- 1024 : Think outside PVS
- 2048 : Template NPC : This entity is a template for the npc_template_maker. It will not spawn automatically and cannot be used with point_template.
- 4096 : Do Alternate collision for this NPC (player avoidance) Note:This flag is disabled in episodic for player companions because the start scripting input does this.
- 8192 : Don't drop weapons
- 16384 : Ignore player push : Dont give way to player
- 65536 : Follow player on spawn : Causes the citizen to follow the player when it spawns. It won't join the player's squad until it gets close enough.
- 131072 : Medic : Turns the citizen into a medic that can heal the player and other NPCs in its squad. Citizens with the "Rebel" citizen type adopt a medic uniform.
- 262144 : Random Head : Randomizes the citizen's model in between all available heads from the chosen citizen type.
- 524288 : Ammo Resupplier : Turns the citizen into an ammo resupplier that can replenish the player's ammo.
- 1048576 : Not Commandable : Prevents the citizen from joining the player's squad.
- 2097152 : Don't use speech semaphore (Obsolete: use the keyvalue)
- 4194304 : Random male head : Randomizes the citizen's model in between all male heads from the chosen citizen type. Leaving the original
Random Headspawnflag enabled is optional.
- 8388608 : Random female head : Randomizes the citizen's model in between all female heads from the chosen citizen type. Leaving the original
Random Headspawnflag enabled is optional.
- 16777216 : Use RenderBox in ActBusies. Note:This makes the collision hull surround the model rather than using the human hull. It's more computationally expensive, but necessary when ActBusies involve close proximity to other props/geometry or animate the citizens in a more dynamic way.
- Set facial expression override
- Patrol whenever I'm idle or alert.
- Stop patrolling when I'm idle or alert.
- Make a previously uncommandable citizen commandable
- Set the medic flag on. Will not change the model or skin of the citizen.
- Set the medic flag off. Will not change the model or skin of the citizen.
- Set the ammo-resupplier flag on. Will not change the model or skin of the citizen.
- Set the ammo-resupplier flag off. Will not change the model or skin of the citizen.
- Set readiness to calmest state (Bored)
- Set readiness to moderate (Alert)
- Set readiness to highest. (Combat imminent)
- Lock readiness at current setting for x seconds -1 = forever, 0 = unlock now
- Gives the NPC the specified weapon - excluded from FGD
- Forces the NPC to speak an idle response - excluded from FGD
- Remove from player squad, instantly.
- Set readiness to panic state (Special)
- Move with this entity. See Entity Hierarchy (parenting).
- Change this entity to attach to a specific attachment point on its parent. The entity will teleport so that the position of its root bone matches that of the attachment. Entities must be parented before being sent this input.
- As above, but without teleporting. The entity retains its position relative to the attachment at the time of the input being received.
- Removes this entity from the the movement hierarchy, leaving it free to move independently.
- Use this input to teleport the NPC to a hint node with the "Player Squad Transition Point" hint type
- This NPC will (or will not) always teleport to a Player Squad Transition Point even if they're not within the trigger_transition
- Decide whether the game should end if this character dies
- Enable/disable weapon pickup
- Gives the NPC a weapon immediately
SetRelationship <string|targetname or classname> <string|disposition> <int|rank>
- Changes whether this NPC likes or dislikes certain others. Used like the ai_relationship entity, with this NPC as the subject.
- Values for
- Set the NPC's health.
AddHealth <int>(New with Source 2007)
RemoveHealth <int>(New with Source 2007)
- Add to or remove from the NPC's health.
- HACK: Sets this NPC's body group (from 0 - n).
- Scales the damage taken when this character is hit by a physics object. 0 means this feature is disabled for backwards compatibility.
- Burst into flames.
- Ignite for the given number of seconds.
- Ignite with the given number of hitbox fires.
- Ignite with the given hitbox fire scale.
- Smash into pieces. If this is not possible, disappear.
BecomeRagdoll(New with Source 2007)
- Remove itself and instantly become a ragdoll with zero force (just go limp). OnDeath, etc. Outputs will NOT be fired.
- Enter/exit scripting state, where NPCs ignore a variety of stimulus that would make them break out of their scripts. They ignore danger sounds, ignore +USE, don't idle speak or respond to other NPC's idle speech, and so on.
- Start an assault at the given rally point.
- Change the name of this NPC's squad. Leaving the parameter blank will remove the NPC from any existing squad.
- Wakes up the NPC if it is sleeping.
- Clears out the NPC's knowledge of a named entity.
- Gagged NPCs won't speak (or moan, caw, etc.) unless made to be a choreographed scene.
- Ignore danger sounds for the specified number of seconds.
- Force the NPC to holster or unholster their weapon. Ignored if the NPC is scripting or if the NPC doesn't use weapons.
HolsterWeapon, except the weapon is destroyed once it has been concealed.
- Force the NPC to use a dynamic interaction with another NPC. Syntax is
<targetname> <dynamic interaction>.
- Update (or create) this NPC's memory of of the given entity.
- Removes this entity and any entities parented to it from the world.
- Functions the same as
Kill, although entities with a large number of children are killed marginally faster.
- Evaluates a keyvalue/output on this entity. It can be potentially very dangerous, use with care.
<output name> <targetname>:<inputname>:<parameter>:<delay>:<max times to fire, -1 means infinite>
- Fire the
OnUseroutputs; see User Inputs and Outputs.
- Same as a player invoking +use; may not do anything. Can also be invoked by creating an output that does not specify an input.
This input is not included in Valve's FGDs.
<script>(New with Left 4 Dead 2)
- Execute a VScript file from disk, without file extension. The script contents are merged with the script scope of the receiving entity.
<string>(New with Left 4 Dead 2)
- Execute a string of VScript source code in the scope of the entity receiving the input. String quotation may be needed when fired via console. Bug:Warning:Never try to pass string parameters to a script function with this input. It will corrupt the VMF structure because of the nested quotation marks, which then must be removed manually with a text editor.
<string>(New with Left 4 Dead 2) !FGD
- Execute a VScript function in the scope of the receiving entity. Note:This input is missing from some games FGD files.
<origin>(New with Alien Swarm) !FGD
- Set this entity's origin in the map. Note:This input is missing from some games FGD files.
<angles>(New with Alien Swarm) !FGD
- Set this entity's angles in the map. Note:This input is missing from some games FGD files.
- Fires when joins player squad
- Fires when leaves player squad (doesn't include death or deletion)
- Fires when ordered to follow player
- Fires when ordered to a location by player
- Fires when a player +USEs the citizen. (activator is the player)
- Fires when this Citizen's movement fails because he/she is blocked by a dynamic object.
- Fired when this NPC takes damage (activator is the damage inflictor)
- Fired when this NPC is killed (activator is the killer)
- Fired when this NPC reaches half of its maximum health
- Fired when this NPC hears a sound (other than combat or the player)
- Fired when this NPC hears the player
- Fired when this NPC hears combat sounds
- Fired when this NPC establishes line of sight to its enemy
- Fired when this NPC loses line of sight to its enemy
- Fired when this NPC loses its enemy. Usually due to the enemy being killed/removed, or because this NPC has selected a newer, more dangerous enemy
- Fired when this NPC establishes line of sight to its enemy, and that enemy is a player
- Fired when this NPC loses line of sight to its enemy, and that enemy is a player
- Fired when this NPC loses its enemy, and that enemy was a player. Usually due to the enemy being killed/removed, or because this NPC has selected a newer, more dangerous enemy
- Fired when this NPC is hurt by a player (activator is the attacker or vehicle driver (if friendly fire))
- Fired when this NPC is hurt by a player OR by one of the player's squadmates (activator is the attacker or vehicle driver (if friendly fire))
- Fired when this NPC has refused to join the player's squad
- Fired when this NPC enters a sleep state
- Fired when this NPC comes out of a sleep state
- Fired when the NPC starts a forced interaction.
- Fired when the NPC aborts a forced interaction for some reason (target NPC died, couldn't be pathed to, etc)
- "NPCs in actbusies can no longer perform dynamic interactions." To do: What does this mean?
- These Outputs each fire in response to the firing of the like-numbered
FireUser4Input; see User Inputs and Outputs.
OnKilled(New with Left 4 Dead)
- This Output fires when the entity is killed and removed from the game.