In Quake 4, the Berserker is a 7-foot tall, mid-level, humanoid Strogg unit designed for close quarters combat. Its right forearm is a long, metal spike and its left hand is an extendable mace/morningstar. The Berserker is very agile and can close in on targets at an alarming speed. It has an ability to create shockwaves of electricity aimed directly at a target via its blade, either by firing a bolt of lightning directly at a target, or by sending a shockwave through the ground.
Berserkers run straight at the target upon detection, and attack with the blade or the mace. Their blade has reasonably good range and can be used while the player is several feet away. The mace can also be detached and swung as a morning star with a range of several feet. Although they usually charge in a straight line, Berserkers are agile and can hop sideways to dodge gunfire or other projectiles.
Besides point-blank melee attacks, Berserkers also possess a couple of close-combat ranged attacks via the channeling of electricity through their blade arm. Berserkers can slam their blade into the ground and send a wave of electricity through the floor at the target; this attack has a range of more than 15 feet and often catches the target by surprise. They can also fire a bolt of lightning directly at the target with their blade arm which hits instantly and has a range of about 15-20 feet, although this method of attack is seldomly used, it might use this attack if the player manages to keep a distance from it.
Berkserkers are quite fast; they run noticeably faster than humans and many other Strogg units, making them an enemy the player should neutralise first. Attempting to outrun a Berserker is impossible since it will always catch up and attack, which may prove to be deadly at higher difficulties.
The first appearance of a Berserker occurs slightly past the halfway mark of the first level, after which they slowly become more common, eventually replacing Grunts as the game's main melee-using enemy. Usually, there is only one Berserker unit deployed in battle in a certain area, but it is possible for two Berserkers to appear at a time, which could pose a serious threat to the player. Like Gunners and Iron Maidens, they are a mid-level Strogg unit with fairly high durability, and on Normal difficulty it takes about 20-30 machine gun rounds or 3 point-blank shotgun blasts to kill one.
When the convoy comes to a minefield, and Rhodes has to disarm the mines, large numbers Grunts and Berserkers will attack. They can quickly kill Rhodes if the player doesn't act fast.
- The Berserker can be a real threat, especially on higher difficulties and in early levels when you are short in firepower, it can be a major threat to your teammates as well. Because of its speed, running backwards isn't very effective as it will certainly close in on the player's position in a range of a few seconds. At that point the Berserker is likely to engage with the blade, which may be avoided by strafing to the sides.
- If the player tries to move out, it will engage with electricity fired from the right arm in an attempt to stun the player and then move in to close quarters combat. The Morning Star will only be used if the player stands still and lets the berserker attack freely at close range.
- It is imperative that the Berserker is neutralized as quickly as possible once it appears, before it can close in on you and cause moderate damage. The Hyperblaster and Nailgun are very effective against it, as they deal a constant stream of damage and will still be effective at a safe distance. The Nailgun is also effective since it can interrupt a Berserker's attacks, giving the player a much needed advantage, but keep in mind that Nailgun will need some time to spin up the barrel and fire. But since they begin to appear in the first level, use Machine Gun and aim for the head if stronger weapon is not available.
- The Shotgun is the best weapon to use at short range, but its risky and requires skill to aim in a short time, as at such short range the Berserker's powerful attacks will cause the player to fly around, making accurate aiming virtually impossible. Headshots deal enormous to the Berserker so it is advisable to aim for the head at all times. At close range a direct hit from the shotgun has the added advantage of briefly stunning the Berserker, interrupting its attack, thus giving you the chance for follow up shots.
- On Normal difficulty the machine gun also works reasonably well at long range, but on harder difficulties it can take up to 60 rounds to kill a single Berserker, making it fairly ineffective considering how quickly the Berserker can charge towards it's target. A good strategy is to engage the Berserker with Machine Gun or Hyperblaster fire at long range, then quickly switch to the shotgun to finish it off once it reaches medium range, you need heavier guns if you see them coming in pairs, or if they are coming with other tough enemies. Circle around the Berserker with these weapons if you have space to move.
- Explosives from Rocket Launcher and Grenade Launcher are ineffective against Berserkers, because by the time the explosives detonate, the Berserker will most certainly be out of the explosive damage radius, unless the player scores a direct hit.
- If a Berserker is encountered amongst other types of hostiles, neutralizing it becomes a priority. As long as a berserker functions, it will constantly attack its target until either one dies, making it hard to focus on other targets. Keep your distance at all times, as its powerful melee attacks cause moderate or heavy damage depend on the difficulty you are playing. You should retreat to a better spot to deal with the Berseker if the other enemies does not close in on you.
- If you need to cover your teammates or escort them, Berserkers, along with Sentries, should be your top priority to take out, teammates won't attempt to dodge it's attacks and just "sit there and take it", though they will shoot Berserker first, on higher difficulties the Machine Gun can no longer kill them in time. A few stabs will kill your team-mate and it's most likely a game over, especially some of the mission that are requiring them to stay alive for the objective to be achieved.
- As long the Berserker cannot jump, it is possible to get out of reach of its melee attacks by being on a different height level. For example, jumping off a ledge or even just hopping onto a slightly elevated conveyor belt makes it impossible for the Berserker to reach the player. This will force the Berserker to use it's electric attack. Though still damaging, it's not as devastating as its fearsome melee capabilities, which may kill an armored player upon impact on harder difficulties. Jumping can also avoid its shockwave.
- The Berserker's head is nearly identical to the one on a Gunner Strogg unit which could mean that their design specifications are similar. It could also hint at the use of the same stockpile of bodyparts which the Strogg are known to harvest.
- The human skin stretched over Berserker's armor may serve a decorative purpose, like skin on Tank's face in Quake 2, while it may be present to help players to tell him apart from Gunner. If Berserker had no skin on his armor he would look very similar to Gunner.