The P-LAH is a tool that has been modified for combat. It seems that only its design and purpose were taken from the concept of the familiar chainsaw design. Inside the titanium alloy casing is a self-contained micro fusion synthesizer that is capable of producing enough fuel for 10000 years of non-stop operation. However, there is only a 6 month guarantee for all the moving parts and they tend to break very soon after that period. In Serious Sam VR: The Last Hope has limited fuel, and has to be refilled every now and then to be able to use it.
Unlike other weapons, the chainsaw needs to have the fire key pressed down to use it.
This weapon is extremely useful against most varieties of smaller foes, being more effective than the Military Knife against multiple targets.
The chainsaw works very well against Gnaars, as they will simply charge towards the player and have no ranged attacks. When they get into range, they will be unable to strike back due to the damage input of the saw.
It also works well against Scythian Witch-Harpies, especially against those that have been downed from the sky. The player should allow the harpy to perform a melee attack (whilst evading the latter), and should then chop her to pieces while she recovers.
This weapon is extremely effective against Marsh Hoppers, especially when they're in large groups. This is notably the best option for combat in the classic version of TSE. When circle-strafing or retreating to a corner and crouching, almost none manage to land an attack.
If you are feeling gutsy and have a large area to work with, the weapon can be used to eliminate large hoards of Kleers without expending any ammo by circle-strafing around them while using the weapon.
The saw is also prohibited to be used against long-ranged fire enemies such as Major Bio-mechanoids and Fiendian Reptiloid Demons (with its powerful melee attack). Their weapons can harm the player in if you use the chainsaw to attack them at close range.
Like the knife, the chainsaw has a deceptively large range for a melee weapon. Take advantage of this.
During early development of The Second Encounter, the chainsaw had a different sound and viewmodel. The chainsaw sounded more like a buzzsaw and its blades were much longer than that of the final model.