Strider

Strider
General information
Faction	Combine
Type	Heavy assault Synth; Heavy Construction Transport;
Individual information
Health	5 (Easy), 7 (Normal), 7 (Hard) RPG hits; 6 (Easy), 10 (Normal), 14 (Hard) Energy Ball hits;
Weapon(s)	Particle cannon aka minigun; Warp cannon aka Gauss cannon; Spiked limbs;
Game information
Entity	npc_strider
Designer(s)	Ted Backman (appearance); Bill Fletcher (animations); Tom Leonard (artificial intelligence);

"Oh my God... Striders really tore the hell out of this place..."

― Alyx Vance^[src]

The Strider is a gigantic tripodal assault Synth used by the Combine. Widely encountered in Half-Life 2, its expansions, and Half-Life: Alyx, it often acts as a powerful sub-boss.

Overview[edit]

Strider among City 17 rubble.

The Strider is a towering Synth with three slender segmented legs protruding from a sleek brown beetle-like body. Boasting destructive firepower and immense strength, they serve as the Combine's main heavy-ground assault units, and are essentially "mobile guard towers".^[7]

Like other Synthetic creatures, Striders are the fusions of organisms and machines. They retained a lot of insectoid traits, such as compound eyes on their heads and fleshy growths on their joints and undersides. In addition, Striders will leak a yellow substance when damaged, and their carapaces contain a cerebral biological unit that looks very much like a larger human brain. While walking about or attacking, they produce a host of different electronic vocalizations, such as growls, groans, whoops, and howls; when killed, they give a mournful cry.

The Strider is an excellent example of the Combine's use of Synths to control the population. Its huge size and intimidating weapons make it ideal for suppressing revolutions and preventing large-scale uprisings. Individual Striders are often used to patrol off-limits City 17 streets and provide heavy support for groups of soldiers. However, in full-scale military combat, Striders are deployed instead in groups as heavy artillery to destroy all structures in an area to flush out entrenched hostile forces. Striders fit both roles well due to their various weapons and remarkable maneuverability on even the harshest terrain granted by their tripodal structure. Despite their height, Striders can crouch down in low spaces to chase enemy combatants and blast away underground obstacles with their warp cannon.

In the wilderness, Striders are often escorted by Hunters which can dispose of smaller threats; In enclosed urban areas, Shield Scanners may also accompany an individual Strider and act as spotters for it, providing situational awareness and extended sight where the huge Synth cannot see. Striders may also be transported to and from combat zones by Combine Dropships, when they will fold their legs into a compact shape that allows easier transit.

As seen in the newspapers found throughout City 17 and Black Mesa East, Striders apparently took part in the Seven Hour War, as one can be seen on the right of the United Nations building, though noticeably larger in size.

Construction Strider[edit]

A Construction Strider.

In the early chapters of Half-Life: Alyx, an unarmed variant of the Strider known as a Construction Strider is seen traversing the rooftops of buildings. These Striders specialize in aiding with construction and maintenance.

Instead of the standard tan exoskeletons, Construction Striders have off-white ones with black markings. They are modified structurally in several ways: they have their pulse turrets replaced with a single robotic camera aperture, and they have the elongated tips of their feet removed to accommodate extra climbing and supporting apparatus affixed to their legs; they also have a cable connecting device in place of the warp cannon, which is used to lift electrical wires and connect them to Combine outlets. They also carry a platform on their heads where Combine Workers can ride atop. On the platform is a mechanical arm with a welding torch, a set of binoculars, and what appears to be a generator pylon. A set of mechanisms keeps this platform level and prevents its occupants from falling off when the Strider moves.

Weaponry[edit]

Striders are both well-armed and armored, making them formidable foes in combat. Their tough exoskeletons are able to withstand multiple RPGs and are completely impervious to small arms fire.

Striders possess two forms of ranged weaponry: one is a rapid-fire anti-personnel particle cannon,^[2] also called a minigun,^[3]^[4] mounted on a ball turret between their eyes, and the other is a charged warp cannon,^[2] also known as a Gauss cannon,^[4] slung under their abdomen. This cannon not only causes scenic destruction, but also inflicts massive splash damage that will vaporize anything in proximity to the area of impact. Prior to the warp cannon's discharge, a thin blue laser indicates its aim and the air surrounding the cannon's barrel will be distorted by a blue aura. In melee combat, the Strider can use their legs, which are tipped with sharp spikes and a circle of fine spines, to impale targets or kick obstacles away.

In Half-Life 2, the Strider's particle cannon does a large amount of damage-approximately 20-30 per shot. It fires in bursts of around a dozen shots at a time, and is programmed to automatically miss with the first few shots before nailing its target with pinpoint accuracy with the last few shots, giving the player time to seek cover. In Episode One, the particle cannon is far more accurate and has a faster (and variable) rate of fire, at the cost of less damage-approximately 5-10 per shot, in order to balance gameplay.

Appearances[edit]

Half-Life 2[edit]

Striders walking in the Citadel.

In Half-Life 2, the Strider is first glimpsed walking along a cordoned-off street with a City Scanner near the Trainstation Plaza.

Striders are seen again much later in the game, during the chapter "Follow Freeman!" in the Overwatch Nexus battle. There, Gordon must defeat several Striders with the help of other Rebels, firing with their RPGs from the ground and the roofs. Soon after, a Strider confronts Gordon who is trying to hide in a building, which is where the Strider is seen working with Shield Scanners that always reveal Freeman's presence wherever he tries to hide. Right after that building, Gordon finds himself in another battle and must defeat Combine soldiers and Striders with other Rebels. After killing all Striders, Gordon reunites with Barney and Dog and enters the Citadel.

Within the Citadel, Freeman sees walking Striders ready to be released into the field, and defeats one in a corridor some time later.

Half-Life 2: Episode One[edit]

In Episode One, a Strider is seen by Gordon and Alyx inside the Citadel carried by a Dropship which crashes shortly after taking off, sending the Strider limply plunging down.

They are met again when the duo emerge from the City 17 Underground and see that Kleiner has taken over the Breencast network. There a Strider is seen afar walking among the rubble and does not notice the two. The Striders are presumably responsible for most of the damage done to the city.

Later at the Technical Trainstation, a Strider and several Combine Soldiers attempt to prevent Gordon and Alyx from leaving the city, acting as the game's final boss fight. The player will be required to hit this Strider with seven RPG rockets, in any difficulty mode. After successfully defeating it, Gordon and Alyx finally leave City 17 via train.

Half-Life 2: Episode Two[edit]

Dog about to prove his value against a Strider, as seen in the Episode Two trailer.

In Episode Two, Striders are first seen among a Combine convoy proceeding towards White Forest.

Some time after, at a short distance from the White Forest base, Gordon and Alyx are blocked by an apparently dead Dropship with an unconscious Strider. It suddenly wakes up, but Dog emerges from the forest and jumps at it. A spectacular battle ensues, ending when Dog rips open the Strider's carapace and removes its brain.

Striders are last seen during the White Forest battle, where they are deployed in large numbers to impede the rocket's launch. To defeat them, Gordon must throw Magnusson Devices, also known as Strider Busters, at the Strider's main body with the Gravity Gun, then detonate them by shooting them with a firearm. During the battle, it is possible for the Striders to destroy many of the surrounding buildings. After Freeman has taken them all down with the help of other Rebels, the rocket is successfully launched.

Half-Life: Alyx[edit]

In the first chapter of Alyx, several Construction Striders are encountered. The first one is seen in a distance from the opening balcony; the second one climbs onto the roofs of Alyx's Hideout plugging a cable, and damages the shingles on the roof; and a third one walking down an alley adjacent to Russell's Lab accidentally destroys his drone.

Towards the ending of the game, two downed regular combat Striders are seen: one right after Alyx crashes the Vault, and the other inside a collapsed parking garage. Two Combine Grunts stand next to the second one, with one of them trying to kick it to wake it up again, only for Overwatch to tell him to stop. Both Alyx and Russell initially believe it to be dead, while the latter remarks that it would be terrible if it came back to life, moments before it really does when Alyx activates a lift and starts to pursue her through the wreckage, which she calls "textbook jinxing". The Strider fires upon Alyx, breaks surrounding structures with its carapace, and uses its warp cannon to clear rubble to gain visual on her while she tries to escape from supporting Combine troops. She then reaches a mounted cannon and starts to fire upon the Strider until it takes enough damage to wail out in pain and fall dead into the rubble.

Tactics[edit]

Striders tend to follow specific patrol routes when tasked with defending a certain area, making them fairly easy to avoid. However Shield Scanners sometimes accompany them, functioning as spotters for the Strider, searching inside buildings and other places of concealment for targets the tripod would otherwise be unable to see. However, this symbiont behavior between the two units is only seen after the Overwatch Nexus battle.

Due to their incredibly high damage output and pinpoint accuracy on their last few hits, taking cover plays an extremely important role while fighting Striders. Often, instead of fighting in the open, one is much less likely to die while only running out of cover when running to another spot or when launching a rocket.

Striders are often rather unaware of their opponents - this is most obvious during the battle outside the Overwatch Nexus. This can be exploited to avoid a lengthy and hazardous battle against many partially avoidable Striders since when only one or two Striders remain, they can be bypassed.

After the Magnusson Device, the most powerful weapon against Striders, the RPG is the most efficient weapon, as its rockets do the most damage, though it takes up to 7 rockets just to kill one in Normal mode. Grenades, Submachine Gun grenades, and Energy Balls do about half the damage of a rocket. Unlike Gunships, Striders tend to ignore all projectiles launched at them, focusing on attacking the player instead.

Using the Magnusson Device against a Strider is not advised until all nearby Hunters are defeated, as they will fire at the device as soon as they see it.

On harder difficulties, Striders tend to duck from flying rockets, which should be anticipated when firing.

It is advised to fire rockets aimed at the "knees" of the Strider. The explosion will severely cripple the Synth, slowing down its movements.

Related Achievements[edit]

Half-Life 2
	Giant Killer (10G)
	Survive the rooftop Strider battle in the ruins of City 17.
Half-Life 2: Episode Two
	Neighborhood Watch (35G)
	Save all buildings outside the missile silo from destruction.
	Defensive of the Armament (20G)
	Save the missile silo from the Combine offensive.
Half-Life: Alyx
	Textbook Jinxing
	Wake the Strider.

Behind the scenes[edit]

Concept very similar to the final version, dated 2001.

Valve's Bill Fletcher used a giraffe/gorilla combo as animation reference for the Strider. He wanted the creature to capture the gracefulness of a giraffe and stomp and lead with its elbows like a gorilla when it walks, to convey a simian power.^[5]

At some point in Half-Life 2’s development, the Strider's synthetic exoskeleton was pale white like the Combine Super Soldier, the Combine Assassin, or the Combine Elite.^[5] It was scrapped early on, however the idea returned in Half-Life: Alyx and is given to the new Construction Strider.

Early concepts depict the Strider with different heads, such as one only consisting of a cannon.^[5]

Several early iterations also bore miscellaneous markings, notably a maroon circle with a "Z" or a lightning bolt in the middle, and some sort of L with a small dot at the opposite angle.^[5]

It was originally to be met in the Coast levels, at least near the Air Exchange.^[5]

According to one of the concept art pictures featured in Raising the Bar, the Strider's current design was already defined as early as 2001 (as seen in the date in Ted Backman's signature).^[5]

As seen in the Half-Life 2 leak source code, the Hopwire Grenade was originally to be the weapon of choice against Striders,^[8] replaced in Episode Two by the Magnusson Device. This is confirmed in the Episode Two commentary, in which Valve's Joshua Weier states that the Magnusson Device "started life as a Half-Life 2 weapon called the Hopwire".^[9]

The Strider appears in several E3 demonstrations: "Strider" (2002), "Kleiner's Lab" (2003), and "Striders" (2003). In "Strider", several Striders chase gas-masked Citizens through ruined streets, and one of the Striders destroys an arch building. In "Kleiner's Lab", a Strider interrupts a conversation between Alyx and Kleiner in the latter's lab. "Striders" feature the 2002 demo in a more recent setting.

The Half-Life 2 source code reveals that the Strider's warp cannon was originally a giant Immolator. This is evidenced by the leftover console variable strider_immolate as well as a comment for the Strider's attack that states "let the immolator works its magic". In fact, the Strider didn't use its warp cannon in the WC map pack maps until the 2003 E3 demonstrations "Striders" and "Kleiner's Lab". The building with the archway it used its warp cannon on in "Striders" was only blasted with its pulse minigun in its E3 2002 equivalent, "e3_strider".^[3]

As seen in the playable Half-Life 2 leak, it was at some point possible for the player to assault Striders, ride them and take their gun after killing them. Noclipping to the Strider's head, then pressing the Use key results in the player seeing through the creature's eyes. At that point, the only thing to do to free oneself is to kill the creature, for instance with the RPG (as the only way to kill a Strider in the playable Half-Life 2 leak is by standing inside its head), or reload the game. When killing it, the Strider collapses, releasing the player. At that point, the red ERROR model appears. When walking through it, the player acquires the Immolator. As a side note, the Immolator worldmodel exists and should appear instead of the ERROR model.

The Strider is an indirect successor to the Combine Super Soldier.^[5]

The cut Combine Guard Gun is a similar weapon to the Strider's cannon (it was also to be used against Striders, according to the leaked game source code); the cut Vortex Hopwire also produces similar effects. The cut Black Hole Gun, originally designed for Quiver, is also similar.

Dog challenging the Strider in the Episode Two trailer.

In the Episode Two commentary, information is given about the spectacular battle between Dog and the Strider:
- According to Valve's Ken Birdwell, the Strider for that sequence was custom-built and, with big parts of it being ripped off and "goo" being spewed everywhere, was used as a test bed for new modeling technology and Valve's new particle system introduced in Episode Two. He further adds that with their episodic process, a lot of new technology comes online throughout development. Since any new technology takes a year or more to really work out all the bugs, they like to look for isolated areas - like this one - where they can test out new things without risking all the things they already know work. They did the same thing with HDR in Lost Coast; once they are sure they did not break anything, they can move the features back into general use. Since this considers the Strider has worked out really well in that sequence, it will be the new Strider as they move forward, and they will be applying what they have learned to any new monsters in Episode Three.^[9]
- Bill Fletcher adds that their main goal with that scene was to create "a cinematic battle of the titans", Dog vs. a Strider. While they were excited about the early implementations, it became obvious that players were uncertain of their role in the scene. Originally the confrontation built slowly with Dog squaring off against the Strider, but having such a slow beginning proved problematic. It looked good in the Episode Two trailer, but did not play well in the game. Instead of the slow build, the team decided to send Dog straight into the action. He makes a grand entrance, jumps on the Strider and the fight begins. The quick start helps to grab the players' attention instead of giving them too much time to worry about what they should be doing.^[9]

According to John Guthrie, the massive Strider battle near White Forest was in production longer than any other map in Episode Two. Tuning it required many, many months of testing and iteration to address playtest feedback, and this was complicated by the fact that every time the team playtested, they saw individuals adopt completely different approaches to defeating the Striders. Some threw logs at Hunters; others relied on their Rebel companions to kill them. Some players never sprinted, while others never used the car. They tried to keep supporting all the different strategies that occurred to players so that their experiments with tactics would be rewarding rather than frustrating. Meanwhile, they had to make sure the Strider and Hunter behaviors were consistent, and balance the experience so that it would be a satisfying game experience for all different play styles at every skill level.^[9]

According to a comment section in Half-Life 2's source code, the Strider originally had a bug where its particle cannon's damage per shot to NPCs was based directly on the ammo capacity (15), when it was assumed that original damage was 8. This was fixed in an update and finally fixed in Episode One. When shipping The Orange Box, the Strider's ammo was changed to 15 for Half-Life 2 and 5 for Episode Two.^[3]

Trivia[edit]

Gas mask Rebels fleeing a Strider in the map e3_strider, in one of the earliest Half-Life 2 screenshots.

The only way to spawn a Strider via the console is to activate "noclip", go up to at least the creature's height, and type into the console "give npc_strider". It will not use its warp cannon and will only walk if the target moves out of its line of sight and if the map has the necessary node structure.

Striders closely resemble the "tripods" described in H.G. Wells' The War of the Worlds, especially the warping cannon, which is much similar to the Heat-Ray from the aforementioned novel. Earlier Strider concept art further exemplifies the similarities.

The Strider has a strange method of firing with its particle cannon, a variation of walking (that is, firing at a point near a target and slowly aiming towards it). It seems that when it focuses on a particular enemy, it fires a long string of shots: the first ones do not hit, but unless the enemy goes behind cover, the last few will always hit. However, this has been removed in Episode One, notably in the final Strider battle.

Gunships and Striders bear the same logo on their back and head, respectively. This logo was on the back of the Combine Soldier's old skin (in white) and can also be seen on the shoulder of one of the Combine Synth Elite Soldier versions. Its meaning and whether it is a Combine logo or not or if it proves a closer relation between the Gunship and the Strider are unknown.

The Strider is referred to as "he", not "it" by Valve employees.^[5]^[9]

If a Strider gets close enough to the antenna outside White Forest, it will destroy the antenna in a single shot with its warp cannon. Afterwards, the message "The rocket has been destroyed – Magnusson's misgivings about the Freeman are completely justified – The game now ends" is shown, and the most recent save loads.

As stated in The Final Hours of Half-Life: Alyx Striders are scanned by the Combine on their home world and recreated later. The Construction Strider as it appears in Half-Life Alyx is an early variant that is not a perfected recreation compared to the Striders seen in Half-Life 2.

In the Half-Life: Alyx Soundtrack, the track that plays when the Parking Garage Strider initially wakes up is titled Cauterizer. This could hint toward the Overwatch designation for a Strider.

Gallery[edit]

Concept art[edit]

Studies of different heads.
Early Strider, with the head only consisting of a cannon.
Ditto, showing a cream-white body with red markings.
Ditto.
Ditto, with a longer neck.
Another study with the body and the head clearly divided.
Concept very similar to the final version, dated 2001.
Head symbol featured in the previous image, and the third of the gallery.
Model render.
Promotional artwork of Gordon battling Antlions and Striders.
Dog vs. Strider poster.
A Construction Strider in promotional artwork for Half-Life: Alyx.