Half-Life Wiki
Half-Life Wiki
This subject is from the Combine era.This is a good article.

The Mortar Synth is an incomplete Half-Life 2 aerial enemy only glimpsed towards the end of the game in the Citadel on a conveyor belt along with the Crab Synth, during Gordon Freeman's second pod ride. It is unknown where it is transported to, as it is never encountered in combat anywhere during the game or its episodes. With the Crab Synth, it is said to be "the backbone of the Combine's subsequent armies".[1]


D3 citadel 050367

Mortar Synths in the Citadel.

The head of a Mortar Synth resembles that of a shrimp or a prawn, and consists of a fleshy, triangular body with a mortar located on its back. Its front end features many spiked protrusions and various mechanical systems. Hovering low above the ground, it was to use its mortar to throw "energy grenades"[2] flinging upwards its rear section, similar to a catapult as well as a laser at the player (similar to the Wasteland Scanner).

Behind the scenes[]

  • The Mortar Synth was never completely finished and seems to bear a temporary name, likely related to its use of a mortar (with the Crab Synth, it is one of the only Synth to have "Synth" in its name). It has incomplete animations, model errors, both high and low quality textures and missing files. This is likely why it is only glimpsed and not confronted during the game.
  • It is likely one of the earliest created Synths (with the Crab Synth), when they bore more red and yellow and did not feature any Combine logo (see also the original Dropship). Ted Backman subsequently defined the current design, with more blue and more pale colors. Added to the fact that it is incomplete, it can be seen as an Easter egg of the early Synth designs, while still canon.
  • The player was originally to directly confront the Mortar Synth in several situations; in the Skyscraper and during the City 17 street battles, among others.[3]


List of appearances[]


  1. Half-Life 2 Prima Guide
  2. "skill.cfg" in the Half-Life 2 files
  3. WC mappack