Story-wise, these NPCs are officially known as "Civil Protection" and are the Combine's thought police and the primary police force seen throughout City 17 and its surrounding areas. They beat citizens in the beginning of Half-Life 2 and get beaten by citizens at the end of Half-Life 2. npc_metropolice is much weaker than npc_combine_s in strength, arsenal, and tactics, but its animations are (fittingly) much more natural and help to establish an effective authoritative atmosphere under the right circumstances.
npc_metropolice is effective at attacking in groups and, when equipped with pistols, will constantly advance towards the enemy. Other than this, however, tactics are mostly limited to taking cover to reload and retreating when taking enough damage. This can change drastically with the help of external elements like ai_goal_standoff or ai_goal_assault, both of which npc_metropolice has unique lines for, or scripted events.
If a npc_metropolice is armed with an SMG and the player is in the airboat, the cop can "stitch" by shooting a meandering, closing path of bullets into the water in front of the vehicle. See the "Always stitch" and "No far stitching" spawnflags for more control over usage and range.
Optionally, a npc_metropolice can carry up to two manhacks on their right shoulder. Before it's deployed, the manhack is nothing more than a harmless bodygroup. This turns into a real manhack the moment it's taken off of the shoulder. To deploy a manhack, the npc_metropolice will take the manhack and throw it upward, causing it to defy gravity and deploy in midair. Determining when to deploy the manhack depends on whether they're in a squad with multiple manhack-wielding metropolice or not. If they're in no squad or the only npc_metropolice with a manhack, they will deploy it as soon as they see an enemy. If multiple npc_metropolice in the squad have manhacks, or if a single npc_metropolice has more than one manhack, only one will deploy and the other(s) will wait for the right opportunity. If a npc_metropolice dies with a manhack still on their shoulder, the manhack will remain a bodygroup and will be lost forever. If the npc_metropolice dies with the manhack in their hand, however, the npc_metropolice will let go of the manhack and it will deploy regardless.
Throughout the chapter Point Insertion of Half-Life 2, npc_metropolice will act very differently. This is due to a global state, gordon_precriminal, that completely changes their attitude towards the player. They will essentially treat them as a regular citizen. (albeit differently from npc_citizen) They will always watch the player when within a certain distance and have unique idle sentences that suggest a calm and secure atmosphere.
They will issue and remember warnings to the player when they do anything to make them angry, ranging from walking into them to hitting them with an empty tin can. They have three warnings, but most agitators go directly to the third warning.
The most common agitator is getting too close to a npc_metropolice. If no warnings have been given, the npc_metropolice will push the player away and give them a warning. If the player has already been warned, the npc_metropolice will threateningly activate their stunstick before pushing them away again and warning them a second time. If the player has been warned three times, they will attack the player with their stunstick from that point forward with no additional consequences of pestering them further. The npc_metropolice will still react differently to the player's presence with the third warning, activating their baton as soon as the player gets within watching distance.
Another agitator is throwing a physics object at the npc_metropolice. This will instantly set the warnings to 3 and cause them to chase the player for 3-7 seconds. If they cannot respond to this (in a script or lacks the "Allowed to respond to thrown objects" spawnflag), the nearest npc_metropolice allowed to respond will chase the player instead.
The only other agitator is pressing +USE on them, which simply adds a warning to the number of warnings or, if the player has already been given 3 warnings, causes them or a nearby npc_metropolice to chase the player.
This behavior is almost completely absent if the npc_metropolice is wielding anything other than a weapon_stunstick. Their behavior will only consist of pushing. To do: Test non-stunstick-wielding pre-criminal cops that are allowed to respond to thrown physics objects
All of this behavior is changed drastically with the use of ai_goal_police.
Dedicated Console Variables
- sk_metropolice_health <int>
- A metrocop's spawn health.
- sk_metropolice_stitch_reaction <int>
- How close to the airboat should Metrocops begin stitching.
- sk_metropolice_stitch_at_hitcount <int>
- Number of times a stitching Metrocop can hit a nearby player.
- sk_metropolice_stitch_behind_hitcount <int>
- Number of times a stitching Metrocop can hit a player looking at it.
- sk_metropolice_stitch_tight_hitcount <int>
- Number of times a stitching Metrocop can hit a player from behind.
- sk_metropolice_stitch_along_hitcount <int>
- Number of times a stitching Metrocop can hit a player looking left/right.
- Values for
- Target Path Corner (target)
- The path_corner that this NPC will move to after spawning.
- Squad Name (squadname)
- 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)
- 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)
- Limits NPC to using specified hint group for navigation requests, but does not limit local navigation.
- Sleep State (sleepstate)
- 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)
- Auto-wake if player within this distance
- Wake Squad (wakesquad)
- Wake all of the NPCs squadmates if the NPC is woken
- Enemy Filter (enemyfilter)
- Filter entity to test targets against
- Ignore unseen enemies (ignoreunseenenemies)
- Prefer visible enemies, regardless of distance or relationship priority
- Physics Impact Damage Scale (physdamagescale)
- 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 (disableshadows)
- Prevents the entity from creating cheap render-to-texture shadows, or lightmap shadows if the entity is a
prop_static. Does not affect shadow mapping.
- Disable ShadowDepth (disableshadowdepth)
<boolean>(New with Portal 2)
- Used to disable rendering into shadow depth (for projected textures) for this entity.
- Projected Texture Cache (shadowdepthnocache)
<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 (rendermode)
- Set a non-standard rendering mode on this entity.
- Render FX / Transparency (0 - 255) (renderamt)
- Transparency amount, requires a Render Mode other than Normal. 0 is invisible, 255 is fully visible.
- Render Color (R G B) (rendercolor)
- Color tint.
- Disable Receiving Shadows (disablereceiveshadows)
- Prevent the entity from receiving shadows on itself.
- Render FX (renderfx)
- Preset pattern of appearance effects.
- Pitch Yaw Roll (Y Z X) (angles)
- 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 (vscripts)
<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 (thinkfunction)
<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.
- Allow Physics Gun (gmod_allowphysgun)
<boolean>(Only in Garry's Mod)
- If set, players cannot use Physics Gun on this entity.
- Sandbox Tool Whitelist (gmod_allowtools)
<string>(Only in Garry's Mod)
- If set, only given tools can be used on this entity. You need to supply the tool class names, the names of the .lua files of those tools. This also includes the context menu properties!
- Waiting to Rappel? (waitingtorappel)
- If yes, this NPC spawns suspended in air and awaits a
BeginRappelinput. It will then spawn a zipline and slide down. When it hits the ground, NPC will cut away the line and try to move forward a few feet to make room for the next NPC. The NPC will not attempt to clear its landing space if it cannot do so by taking a few steps forward.
- What weapon this Metrocop should spawn with. Choices are:
- Pistol Tip:Cops have bad aim with the pistol, so they will periodically take a couple steps toward the player if they can path to him.
- Stun Stick
- Shotgun Bug: This NPC doesn't have proper animations for this weapon. Since all male characters share the same skeleton, however, the Metrocop can easily be given the Combine Soldiers' animations to compensate.
- Number of Manhacks
- Each Metrocop can carry and deploy up to two npc_manhacks.
- Pistol starts drawn
- Whether or not the NPC's pistol should start holstered. The pistol cannot be unholstered with the UnholsterWeapon input and can only be unholstered when the NPC spots an enemy. Has no effect on other weapons.Note:When an officer's pistol starts undrawn, it actually starts invisible and becomes visible after they play the unholoster animation. They will still use pistol animations and they are susceptible to the bug below.
- 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
npc_template_maker. It will not spawn automatically and cannot be used with
- 4096: Do Alternate collision for this NPC (player avoidance) Note:This flag is disabled in episodic for player companions because the
StartScriptinginput does this.
- 8192: Don't drop weapons
- 16384: Ignore player push (New with Half-Life 2: Episode One / Source 2006): Don't give way to player
- 131072 : Simple cops : Lowers the NPC's health to 26 instead of 40 and uses more dramatic flinch animations for certain hit-boxes. Used in the early canal levels of the game.
- 524288 : Always stitch : This forces the stitching behavior to occur. If the metrocop is armed with an SMG and the player is beneath them, they will shoot a meandering, closing path of bullets.
- 1048576 : No chatter : Automatically gags the NPC and supposedly prevents some metrocop-specific speech that standard gagging doesn't. This is now believed to be non-functional.
- 2097152 : Arrest enemies : Causes the cop to "arrest" its opponents. Demonstration Video
- 4194304 : No far stitching : Stops stitching if the player is over 6000 units away.
- 8388608 : Prevent manhack toss : Prevents the cop from deploying their manhack(s). See the EnableManhackToss input.
- 16777216 : Allowed to respond to thrown objects : Only useful in pre-criminal mode. Allows the officer to chase players who have annoyed them. This does not override the settings of an
- 33554432 : Mid-range attacks (halfway between normal + long-range) : Extends the metrocop's preferred attack distance to 3500 units.
- Enables manhack toss (which had been disabled by the spawnflag)
- Causes the NPC to police the area defined by an ai_goal_police.
- Makes the NPC flick a held weapon_stunstick on.
- Start rappelling now.
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.
<integer>(New with Half-Life 2: Episode Two / Source 2007)
<integer>(New with Half-Life 2: Episode Two / 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 Half-Life 2: Episode Two / 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.
HolsterWeapon(New with Half-Life 2: Episode One / Source 2006)
UnholsterWeapon(New with Half-Life 2: Episode One / Source 2006)
- Force the NPC to holster or unholster their weapon. Ignored if the NPC is scripting or if the NPC doesn't use weapons.
HolsterAndDestroyWeapon(New with Half-Life 2: Episode One / Source 2006)
- Same as
HolsterWeapon, except the weapon is destroyed once it has been concealed.
ForceInteractionWithNPC <string> <string>(New with Half-Life 2: Episode One / Source 2006)
- Force the NPC to use a dynamic interaction with another NPC. Syntax is
<targetname> <dynamic interaction>
UpdateEnemyMemory(New with Half-Life 2: Episode One / Source 2006)
- Update (or create) this NPC's memory of of the given entity.
<float>(Only in Garry's Mod)
- Sets the maximum look distance for the NPC. Defaults are 2048 and 6000 for long range NPCs.
- Sets the entity's transparency to a number from 0 (invisible) to 255 (fully visible). Requires the entity to have its Render Mode (rendermode) set to a number other than
- Sets an RGB color for the entity.
- Turn dynamic shadows off for this entity.
- Turn dynamic shadows on for this entity.
DisableReceivingFlashlight(New with Portal 2)
- This object will not receive light or shadows from projected textures.
EnableReceivingFlashlight(New with Portal 2)
- This object may receive light or shadows from projected textures.
- Removes this entity and any entities parented to it from the world.
- Functions the same as
Kill, although this entity and any entities parented to it are killed on the same frame, being marginally faster than
- 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: In , the code is executed in the script scope of the entity that fires the output, not the one receiving the input.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.
<coordinates>(New with Alien Swarm) !FGD
- Send this entity to a spot in the map. If the entity is parented to something, it will be offset from the parent by this amount.
<angles>(New with Alien Swarm) !FGD
- Set this entity's angles.
- 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(Only in the Left 4 Dead series)
- This Output fires when the entity is killed and removed from the game.
- Fires when the player is hit by a stun stick by this NPC.
OnCupCopped(New with Half-Life 2: Episode Two / Source 2007)
- Fired when this NPC is hit by a prop with the targetname "cupcop_can".
- Fires when done rappelling.