Black Mesa – The Gonarch Research Expedition (Tips & Tricks)

Black Mesa - The Gonarch Research Expedition (Tips & Tricks)
Black Mesa - The Gonarch Research Expedition (Tips & Tricks)

In this guide, I will be going over the behaviours of the Gonarch, a monster encountered in the second chapter of the Xen chapters, appropriately named “Gonarch’s Lair”. I have experienced the entirety of the chapter on every difficulty, so I will give advice and tips of how to overcome this beast. As of now, I am going to cover the main Gonarch battles, but as time goes on I may improve upon the guide and discuss the various chase sequences and include images to further expand upon my point.


Note: Credit goes to Terra-BITE

The Gonarch, generously nicknamed “Big Momma”, is the final stage of the Headcrab’s life cycle and acts as a living nest of sorts for her babies. The Gonarch appears to hunt all other Xenian lifeforms (excluding the Xen Trees and flora) as deceased carcasses of mostly houndeyes and bullsquids can be seen torn apart and scattered around her lair. It is unknown whether the Gonarch consumes creatures she kills as only mangled corpses are left, but she is nonetheless a most definitely ferocious predator of Xen seen from the body count. The Gonarch has adapted in many ways to travel and hunt within her lair, and has been seen climbing over spires and rocks with ease, making her a versatile danger. Unlike other Xen creatures however, she spends her time exclusively within the confines of her lair and waits patiently below ground for prey like the younger Headcrabs. Her armoured carapace covering the legs and upper body seem to be completely immune to bullets and most weaponry, so it is advised to aim for the dangling sac protruding from the Gonarch’s underbelly if met with confrontation, however explosive weaponry proves to be effective against the shell and sac alike. The sac itself is a reproductive organ that births and houses all infant Headcrabs and is shown to be able to release the babies at will if need be during combat. It is proven to be an incredibly difficult feat to kill a Gonarch, and since fleeing is not a valid option in some Xen cave systems,we will be discussing behaviours of the creature and methods to counter it.

Black Mesa - The Gonarch Research Expedition (Tips & Tricks)

The Gonarch, seen destroying a Xenian teleporter.

Methods of Attack

These are short explanations of each form of attack the Gonarch has been seen using during battle. Ways she telegraphs these attacks will also be included. Good ways to avoid the attacks will be shown in a later section.

The Chase Attack

(I’m not sure if this classifies as an attack, since it is technically just the Gonarch running at you, but it’s a means of damaging the target as well so it’s on the list).

The Gonarch has little to no telegraph for this attack. When finishing an attack, sometimes instead of running to another part of the arena to attack, the Gonarch will begin running at the target. Upon reaching the target, the Gonarch will quickly stop and slice at the target with one of her front legs. This attack is difficult to outrun without the assist of the longjump module.

The Charge Attack

The Gonarch will rear up her front legs into the air and slam them down onto the ground, creating a small shockwave near her that can deal damage and remain standing in a pose with her head bent forward slightly. The Gonarch will stay in this pose for around 1 second before charging full speed at the target. She is limited to a single directory while in her charging state and cannot aim well once charging. The attack can send the target flying, but if the Gonarch misses she will, if near a wall, become staggered for a few seconds and get back on her feet. If the Gonarch misses and she is not near a wall when she does so, she will instead slide to a stop instead.

The Throw Attack

The Gonarch will run over to one of the many stone pillars lying on the ground. This telegraph may seem hard to spot, but you should just look for where the pillars are and take note when the Gonarch is running over to one of those spots. The Gonarch will throw a pillar very quickly so it is wise to know when the Gonarch will throw one. The pillars, when launched, can deal substantial damage to the target.

The Mortar Attack

The Gonarch telegraphs this attack when she shuffles and tucks her legs together beneath her. She will remain in this position for a short time before jolting her body down and releasing 3 acidic mortars high into the air in a spray loosely targeting where the target was standing a the start of the jolt and land there. The Gonarch releases 3 bursts of these 3 acidic mortars at a time. Each mortar will release a ring of gas around them upon landing, remain in place for 1 second and explode into green flames, causing considerable damage.

The Splash Attack

The telegraph for this attack is when the Gonarch stands in place for around 1 second. She then begins to shake the sac forwards multiple times, each time producing a group of projectiles that travel horizontally at high speeds. Because of the speeds, they almost always travel across the entire arena. The splash of the projectiles deals no damage. During this attack the Gonarch is completely stationary as she needs to be still for each swing, compared to the mortar attack where the mortars travel independently once she shoots them out so she is free to move during the attack.

The Spawn Attack

The Gonarch will momentarily stand still for around 0.5 seconds before bouncing the sac, causing a horde of baby headcrabs to appear from the bottom of the sac together. The babies will run out around the Gonarch and quickly giving chase towards the target. These babies, while irritating for the target, do not stay for long. Baby headcrabs have been observed to disappear or die some time after being spawned.

The Frenzy Attack

The Gonarch’s telegraph for this attack is hard to use as a signal to dodge, however when she begins the attack she will constantly shoot out unstable mortars for some time. She jolts her body up quickly to deploy mortars with only 1 second resting time between each deployment. The Gonarch will be acting in a violent and reckless state and repeatedly throw out set after set of 3 unstable mortars into the air towards where the target is standing. Unstable mortars do not explode. Instead, they catch fire immediately upon deployment and, upon landing, stay in place creating an area of green flames. These flames take only around 5 seconds to diminish. As the Gonarch repeatedly attacks this way standing in place in the frenzy state, she is completely vulnerable.

Counters to The Gonarch’s Attacks

These strategies have been gathered via personal experience. I feel the need to say that none of these strategies are perfect and sometimes you may not be in the right position to use the counter, but in most cases it is highly recommended to do so when possible.

The Chase Attack

Focus on longjumping forwards towards a column or other structure and then on longjumping to the left or right around the structure. This lets you gain distance from the Gonarch since it takes her longer to turn the corner. Once you’ve gained enough distance, shoot the Gonarch with the rpg as rockets and explosions stun her and cause her to stop chasing you. If she does not, you still have the extra gained distance between you both so you can gather more supplies and shoot the Gonarch again.

The Charge Attack

Because of the Gonarch’s lengthy telegraph for this attack (compared to the others at least) you have much time to initiate this counter. Large columns or other large structures (with the exception of crystals in battle 1) are essential here so keep close to some at all times. For this counter, simply keep an eye on the Gonarch at all times. When you see her start her telegraph for the charge, quickly longjump or run behind a pillar or structure and wait for the impact sound and wail from the Gonarch. If you cannot hear these, just now it should be safe to leave and continue attacking just after a few seconds. However, if you are not near a structure when the Gonarch telegraphs, use this strategy. Wait for the Gonarch to begin charging at you. Start running to the right while still looking at her. When she is just about to hit you, longjump away. If you longjump away when she is charging at you but far away, she will align her charge to your position, but if you longjump when she is very close she has no time to. Since she has a long stutter animation after charging at a structure, use this opportunity to deal damage with the gluon gun, as you want to save its ammo for when the Gonarch is relatively still and her stutter animation causes her to stay still for some time.

The Throw Attack

Make an effort to look at the Gonarch when you can but it is alright to look away when she is chasing you or if you’re behind a pillar. You should also make a mental note of where each pillar is because when the Gonarch runs to one you’ll need to know if she’s running to a pillar to throw it or just to a place to use a different attack. If you can, try to dodge behind a column or structure to avoid the pillar throw but if you cannot find time to do so, simply longjump away to the left or right when the Gonarch stands behind the pillar.

The Mortar Attack

Since the mortars do quite a bit of damage if you’re not careful, you need a way to avoid them well. To avoid them, when the Gonarch starts launching the mortars, stay in roughly one position and continue attacking the Gonarch while she is stationary during the attack, preferably with the gluon gun because of reasons stated before. When all 3 sets of mortars are airborne, use your longjump to jump away to a point where the mortars cannot reach. Since you would’ve been in one place when the mortars were all launched, they will all be grouped up and easy to dodge however do note that the groups are launched around the point you’re standing meaning they won’t be all in the same place so they may take up quite a bit of arena space. Until they detonate and free up the space of the arena, try to gather rockets quickly. They are quick to detonate so don’t worry about being killed by the Gonarch while waiting but still make an attempt to always be moving.

The Splash Attack

This is very easy to dodge. Simply move behind any structure like a crystal, column or rock face. Since the Gonarch is stationary during this attack, you can easily gather more rockets from the supply pods. In battle 2 especially since both pods are put next to the columns.

The Spawn Attack

Bebcrabs simply die off after a few seconds of being out of their mother’s sac and since they are unable to jump that high to block your rockets, you should be able to continue attacking the Gonarch while running around as usual. If you spot the Gonarch telegraphing the attack, try to launch a rocket at the Gonarch in the process. The explosion will deal damage to the Gonarch and also set the majority of the bebcrabs on fire.

The Frenzy Attack

This attack can deal a large amount of damage in a short amount of time, so you need to have a good counter to it. Countering this attack can be difficult, so to minimize the amount of time needed for you to carry out this counter, when the second phase starts, place all of your satchel charges around the group of pillars that the Gonarch will fall onto. After the Gonarch falls down, activate the charges. This will put the Gonarch into the final stretch where she constantly fires out the unstable mortars. Now on to the counter itself. Simply run loops around the Gonarch around the walls of the arena while firing the rpg, gluon and mp5 grenades at the Gonarch. You must be running in circles around the area as the unstable mortars once again target where you are standing but since they’re being fired constantly, you cannot use the strategy from before with the regular mortars. If you see one of the unstable mortars about to land where you need to run, then long jump. Never turn around. Don’t worry about running into previous unstable mortars as the flames with extinguish before you run a loop.

Other Useful Tips

These tips don’t belong to any specific attack and should be used at all times when battling the Gonarch.

  • Always know where the Gonarch is and try to look at her whenever possible to avoid getting surprise attacked.
  • Do not take chances in dodging. Use the strategies given before at all times. If you think you can get a cheeky rocket hit while the Gonarch is charging at you, there’s a high chance you’ll get hit doing so.
  • When longjumping, quickly prss jump twice. Don’t wait between presses. If you press jump twice immediately, the game itself lets you jump a bit before making you longjump. If that doesn’t make sense, just know that if you quickly press jump twice immediately you’ll longjump at the perfect time, minimising the chance of getting stuck on ground objects.
  • When longjumping, try to strafe mid-air constantly to avoid the terrain. This also minimises the chance longjumping right into a wall.
  • When longjumping, never longjump backwards. For example, if you’re trying to run from the Gonarch, don’t look back at her while trying to run. You’ll probably longjump into a wall behind you and get hit by the Gonarch.


The Gonarch is an incredible foe to fight. Each attack feels strategic and they each have their own counters. It’s really a game of learning when to be defensive and when to be offensive and how to avoid the Gonarch’s methods of attack. Each rocket hit feels like a minor victory and even if you do get hit, nothing feels unfair because it feels like it’s your fault. Easy and normal mode feel amazing and fair, but sometimes in hard mode the Gonarch chases you a little too often which may seem unfair, but there is always a counter to it although it has a lesser chance of working. Still though, when you practise and learn all of the counters to the Gonarch’s attacks, the entire fight combined with the extraordinary soundtrack all comes together perfectly.

The personality of the Gonarch portrayed throughout showing that she is trying to do nothing more than protect her home and the bebcrabs and headcrabs while they grow and she actually feels like a cunning predator during battle using actual strategies like knocking down bridges and in the final encounter, when nearing death, the Gonarch acts desperate, launching mortars rapidly and producing the last amount of bebcrabs before death. The Gonarch is a magnificent creature in this chapter in every way.

Helena Stamatina
About Helena Stamatina 2739 Articles
My first game was Naughty Dog’s Crash Bandicoot (PlayStation) back in 1996. And since then gaming has been my main hobby. I turned my passion for gaming into a job by starting my first geek blog in 2009. When I’m not working on the site, I play mostly on my PlayStation. But I also love outdoor activities and especially skiing.

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