npc_citizen

Class hierarchy
CNPC_Citizen ↳CNPC_PlayerCompanion ↳CAI_PlayerAlly ↳CAI BaseActor ↳CAI_ExpresserHost ↳CAI_BaseHumanoid ↳CAI_BaseHumanoidBase ↳CAI_BaseNPC ↳CBaseCombatCharacter ↳CBaseFlex ↳CBaseAnimatingOverlay ↳CBaseAnimating ↳CBaseEntity
npc_citizen17.cpp

npc_citizen is a point entity available in Half-Life 2, Half-Life 2: Episode One, Half-Life 2: Episode Two, and Half-Life 2: Deathmatch.

They are the downtrodden citizens of City 17. They will pick up weapons, fight the Combine, and join the player's squad if they see him.

In code, it is represented by theCNPC_Citizenclass, defined in thenpc_citizen17.hfile.

Note:In Mapbase, this NPC has been modified with new animations and weapon support

Note:Some keyvalues, spawnflags, effect flags, inputs, or outputs might not affect an NPC, based on the functionality and coding of the NPC.

Dedicated Console Variables

Cvar/Command	Parameters or default value	Descriptor	Effect
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 they're 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	Places chefhat.mdl on 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.

Keyvalues

Weapons (additionalequipment) <choices>

Weapon to spawn with.

• SMG1
• AR2
• Stun Stick
• Crowbar
  Note:You can name the citizen "matt" for this to show up as a pipe.
• Shotgun
• Beer bottle (Not coded - Don't use)
• Beer bottle2 (Not coded - Don't use)
• RPG
• Nothing

Bug:In modern builds of Half-Life 2, citizens wielding RPGs will almost never fire them, due to broken self-preservation code. They will always believe they're in danger of hitting themselves, no matter the distance to the target. This is most noticeable on map d3_c17_12 from the chapter "Follow Freeman!"

Note:NPCs can be seen firing rockets in the final fight of Half-Life 2: Episode Two Possibly scripted event? ^[confirm].

  [todo tested in?]

Ammo To Resupply (ammosupply) <choices>

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.

• Pistol
• SMG1
• SMG1 grenade
• AR2
• Shotgun
• RPG
• Grenade
• Crossbow Bolt

Amount Of Ammo To Give (ammoamount) <integer>

Amount of ammo the NPC has (in total) to give to the player.

Type (citizentype) <choices>

Changes the citizen's appearance (but not behaviour).

• Default: The hardcoded default for the given chapter. All custom maps use Downtrodden.
  Note:In Mapbase, mappers can change this value with the hl2_gamerules entity
• 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:The Random Head spawnflag should always be disabled when using Unique citizens.

Expression Type (expressiontype) <choices>

Ambient facial animation.

• 0: Random
• 1: Scared
• 2: Normal
• 3: Angry

Model (model) <choices>

Various model overrides. With the Random Head spawnflag, any of these models except for Cheaple and Odessa may be chosen.

• Cheaple Male 1 is a low-detail model that only works if Type is Downtrodden or Unique.
• Odessa. DO NOT USE. is Colonel Odessa 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.

Facial Expression Override (expressiontype) <string>

Facial expression override

Fire Output When Nav Is Blocked? (notifynavfailblocked) <boolean>

Fires an output when the Citizen's movement fails because he/she is blocked by a dynamic object.

Permanent Squad Member? (neverleaveplayersquad) <boolean> (in all games since )

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 (denycommandconcept) <string> (in all games since )

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.

Parentname:

Parent (parentname) <targetname>

Specifies a movement parent. An entity will maintain its initial offset from its parent. An attachment point can be added to the end of the name, separated by a comma.

PlayerCompanion:

Always transition (AlwaysTransition) <boolean> (in all games since )

This NPC will always teleport to a Player Squad Transition Point if they're not within the trigger_transition.

Prevent picking up weapons? (DontPickupWeapons) <boolean> (in all games since )

This NPC will NOT be allowed to pick up weapons they find on the ground.

Is this a vital ally? (GameEndAlly) <boolean> (in all games since )

This NPC will cause the game to end if killed.

TalkNPC:

Use Sentence (UseSentence) <string>

Sentence spoken when the NPC gets +used by a player

Un-Use Sentence (UnUseSentence) <string>

Sentence spoken NPC gets used again

Don't Use Speech Semaphore (DontUseSpeechSemaphore) <boolean>

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.

BaseNPC keyvalues

CBaseCombatCharacter: Relationship (Relationship) <string> !FGD <string|targetname or classname> <string|disposition> <int|rank> Changes whether this entity likes or dislikes certain other things. Used like the ai_relationship entity, with this entity as the subject. Values for disposition are: D_HT: Hate D_FR: Fear D_LI: Like D_NU: Neutral Physics Impact Damage Scale (physdamagescale) <float> Multiplier for damage amount when this entity is hit by a physics object. With a value of 0 the entity will take no damage from physics. CAI_BaseNPC: Target Path Corner (target) <targetname> The path_corner that this NPC will move to after spawning. Squad Name (squadname) <string> 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 (hintgroup) <string> 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 (hintlimiting) <boolean> Limits NPC to using specified hint group for navigation requests. Does not limit local navigation. Sleep State (sleepstate) <choices> 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 (wakeradius) <float> Auto-wake if player comes within this distance. Wake Squad (wakesquad) <boolean> Wake all of the NPCs squadmates if the NPC is woken. Enemy Filter (enemyfilter) <targetname> Filter entity to test targets against. Ignore unseen enemies (ignoreunseenenemies) <boolean> Prefers visible enemies, regardless of distance or relationship priority. DamageFilter: Damage Filter (damagefilter) <targetname> Name of the filter_damage_type entity that controls which entities can damage us.

Flags

BaseNPC flags

Wait Till Seen : [1] Prevents this NPC from seeing (or being seen) until it enters a player's viewcone. Gag : [2] Won't make IDLE sounds until it's angry. Fall to ground (unchecked means teleport to ground) : [4] Drop Healthkit : [8] Causes this NPC to drop an item_healthvial upon dying. Efficient : [16] Don't acquire enemies or avoid obstacles Wait For Script : [128] Forces this NPC to "wait" in an idle state until it finishes playing a scripted_sequence. Long Visibility/Shoot : [256] By default, increases a NPC's sight range to 6,000 units and allows it to attack from anywhere within that distance. Fade Corpse : [512] Think outside PVS : [1024] Allows this NPC to run its regular AI outside of any player's PVS. Template NPC : [2048] Marks this NPC as a template for entities like npc_template_maker. The NPC will not spawn on its own. This is not needed for point_template. Do Alternate collision for this NPC (player avoidance) : [4096] Note:This flag is disabled in episodic for player companions, because the StartScripting input does this. Don't drop weapons : [8192] Ignore player push : [16384] (in all games since ) Entity won't give way to player.

• Follow player on spawn : [65536]

Causes the citizen to follow the player when it spawns. It won't join the player's squad until it gets close enough

• Medic : [131072]

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.

Warning:In regular Half-Life 2, medics do not account for the player's Z position when giving health. For example, the player could be on the edge of a ledge, and a medic can give them health despite being a considerable distance below. This has been fixed in Episode One and Episode Two.

Bug:Medics don't correctly account for relationship when checking to heal a target, so citizens hostile to the player can still heal them.  [todo tested in?]

Code Fix:This can be fixed in CNPC_Citizen::ShouldHealTarget() by changing the first disposition check to check for pTarget, not !pTarget.

• Random Head : [262144]

Randomizes the citizen's model in between all available heads from the chosen citizen type.

Note:If this flag, random male head, or random female head is checked and the efficient flag is checked, then the citizen's model becomes models/humans/male_cheaple.mdl.

• Ammo Resupplier : [524288]

Turns the citizen into an ammo resupplier that can replenish the player's ammo.

• Not Commandable : [1048576]

Prevents the citizen from joining the player's squad.

• Don't use speech semaphore : [2097152]

Obsolete: use the keyvalue

• Random male head : [4194304]

Randomizes the citizen's model in between all male heads from the chosen citizen type. Leaving the original Random Head spawnflag enabled is optional.

• Random female head : [8388608]

Randomizes the citizen's model in between all female heads from the chosen citizen type. Leaving the original Random Head spawnflag enabled is optional.

• Use RenderBox in ActBusies. : [16777216]
  

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.

Inputs

SetExpressionOverride <string>

Set facial expression override

StartPatrolling

Patrol whenever I'm idle or alert.

StopPatrolling

Stop patrolling when I'm idle or alert.

SetCommandable <boolean>

Make a previously uncommandable citizen commandable

SetMedicOn

Set the medic flag on. Will not change the model or skin of the citizen.

SetMedicOff

Set the medic flag off. Will not change the model or skin of the citizen.

SetAmmoResupplierOn

Set the ammo-resupplier flag on. Will not change the model or skin of the citizen.

SetAmmoResupplierOff

Set the ammo-resupplier flag off. Will not change the model or skin of the citizen.

SetReadinessLow

Set readiness to calmest state (Bored)

SetReadinessMedium

Set readiness to moderate (Alert)

SetReadinessHigh

Set readiness to highest. (Combat imminent)

LockReadiness <float>

Lock readiness at current setting for x seconds -1 = forever, 0 = unlock now

GiveWeapon <classname> !FGD

Gives the NPC the specified weapon

SpeakIdleResponse  !FGD

Forces the NPC to speak an idle response

RemoveFromPlayerSquad  (in all games since )

Remove from player squad, instantly.

SetReadinessPanic  (in all games since )

Set readiness to panic state (Special)

Parentname:

SetParent <string>

Move with this entity. See Entity Hierarchy (parenting).

SetParentAttachment <string>

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.

SetParentAttachmentMaintainOffset <string>

As above, but without teleporting. The entity retains its position relative to the attachment at the time of the input being received.

ClearParent

Removes this entity from the the movement hierarchy, leaving it free to move independently.

PlayerCompanion:

OutsideTransition  (in all games since )

Use this input to teleport the NPC to a hint node with the "Player Squad Transition Point" hint type.

EnableAlwaysTransition  (in all games since )

DisableAlwaysTransition  (in all games since )

If enabled, this NPC will always teleport to a Player Squad Transition Point even if they're not within the trigger_transition.

MakeGameEndAlly  (in all games since )

MakeRegularAlly  (in all games since )

Determines whether the game should end if this character dies.

EnableWeaponPickup  (in all games since )

DisableWeaponPickup  (in all games since )

Enables/disables weapon pickup.

GiveWeapon <classname> (in all games since )

Gives the NPC a weapon immediately.

ClearAllOutputs  (only in )

Clears every output that this NPC has.

TalkNPC:

SpeakResponseConcept <string> (in all games since )

Speak the specified response concept immediately.

BaseNPC inputs

CAI_BaseNPC: ActivateSpeedModifier  !FGD DisableSpeedModifier  !FGD Break Smash into pieces. If this is not possible, disappear. BecomeRagdoll  (in all games since ) Remove itself and instantly become a ragdoll with zero force (just go limp). OnDeath, etc. outputs will NOT be fired. ForceInteractionWithNPC <string> <string>  (in all games since ) Force the NPC to use a dynamic interaction with another NPC. Syntax is <targetname> <dynamic interaction>. ForgetEntity <targetname> Clears out the NPC's knowledge of a named entity. UpdateEnemyMemory  (in all games since ) Update (or create) this NPC's memory of of the given entity. GagEnable GagDisable Gagged NPCs won't speak (or moan, caw, etc.) unless made to be a choreographed scene. HolsterWeapon  (in all games since ) UnholsterWeapon  (in all games since ) Force the NPC to holster or unholster their weapon. Ignored if the NPC is scripting or if the NPC doesn't use weapons. HolsterAndDestroyWeapon  (in all games since ) Same as HolsterWeapon, except the weapon is destroyed once it has been concealed. IgnoreDangerSounds <float> Ignore danger sounds for the specified number of seconds. InsideTransition  !FGD OutsideTransition  !FGD SetBodyGroup <integer> HACK: Sets this NPC's body group (from 0–n). SetEnemyFilter <string> SetHealth <integer> Set the NPC's health. 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 disposition are: D_HT: Hate D_FR: Fear D_LI: Like D_NU: Neutral SetSquad <string> Change the name of this NPC's squad. Leaving the parameter blank will remove the NPC from any existing squad. StartScripting StopScripting 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 NPCs' idle speech, and so on. Wake Wakes up the NPC if it is sleeping. CBaseCombatCharacter: KilledNPC  !FGD Tells the entity it killed something. Despite the name, this can include a player. This input will be automatically sent by the victim when they die. physdamagescale <float> 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. DamageFilter: SetDamageFilter <string> Sets the entity to use as damage filter. Pass in an empty string (no parameter) to clear the damage filter.

Outputs

OnJoinedPlayerSquad

Fires when joins player squad

OnLeftPlayerSquad

Fires when leaves player squad (doesn't include death or deletion)

OnFollowOrder

Fires when ordered to follow player

OnStationOrder

Fires when ordered to a location by player

OnPlayerUse

Fires when a player +USEs the citizen. (!activator is the player.)

OnNavFailBlocked

Fires when this Citizen's movement fails because he/she is blocked by a dynamic object.

BaseNPC Outputs

OnDamaged Fired when this NPC takes damage (!activator is the damage inflictor). OnDamagedByPlayer Fired when this NPC is hurt by a player (!activator is the attacker or vehicle driver [if friendly fire]). OnDamagedByPlayerSquad 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]). OnDeath Fired when this NPC is killed (!activator is the killer). OnDenyCommanderUse Fired when this NPC has refused to join the player's squad. OnForcedInteractionAborted Fired when the NPC aborts a forced interaction for some reason (target NPC died, couldn't be pathed to, etc.). OnForcedInteractionStarted Fired when the NPC starts a forced interaction. OnForcedInteractionFinished "NPCs in actbusies can no longer perform dynamic interactions." Todo: What does this mean? OnHalfHealth Fired when this NPC reaches half of its maximum health. OnHearCombat Fired when this NPC hears combat sounds. OnHearPlayer Fired when this NPC hears the player. OnHearWorld Fired when this NPC hears a sound (other than combat or the player). OnFoundEnemy <targetname> Fired when this NPC establishes line of sight to its enemy. OnLostEnemy 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. OnLostEnemyLOS Fired when this NPC loses line of sight to its enemy. OnFoundPlayer <targetname> Fired when this NPC establishes line of sight to its enemy, and that enemy is a player. OnLostPlayer 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. OnLostPlayerLOS Fired when this NPC loses line of sight to its enemy, and that enemy is a player. OnSleep Fired when this NPC enters a sleep state. OnWake Fired when this NPC comes out of a sleep state.