env_beam and env_sprite
The Warpball is the name of the warp-in effect when aliens from Xen teleport into a location. It can be seen in Half-Life and its expansions. It was first named in the Dreamcast version of Half-Life: Blue Shift.
In Half-Life and Half-Life: Opposing Force, the warpball effect is a combination of entities producing sprites, beams, and sound effects. It appears as a small flashing transparent green ball that emits green light with energy beams projecting out of it. It was replaced in the Dreamcast port of Half-Life with
env_warpball, a single entity which handles all of its creation. This allowed for easier placements of the effect in the maps by level designers. They can be obstructed to prevent the enemies from teleporting in. In Blue Shift and later installments, warpballs damage the player in close proximity when they spawn. This was most likely added to discourage the player from blocking them.
 List of appearances
- Half-Life: Day One (First appearance)
- Half-Life (Dreamcast port) (as env_warpball)
- Half-Life (PlayStation 2 port) (as env_warpball)
- Half-Life: Opposing Force
- Half-Life: Blue Shift (as env_warpball)
- Half-Life: Decay (as env_warpball)
|Black Mesa Incident · Particle Storm · Portal Storm · Resonance Cascade · Superportal · Teleportation · Warpball|