The Rollerball is essentially a rolling version of the Spawner. Its only attack is to roll onto the player.
If the Rollerball is hit with a powerful attack, it will bounce back.
- The Double Shotgun is very effective against a single Rollerball. Two point blank range shots will destroy it.
- If the player encounters a group of Rollerballs from a distance, the rocket launcher is very useful against them. It does good damage to a Rollerball and knocks the Rollerball back, which keeps them a safe distance from the player.
- The RB-45 Hand Grenade is very useful against a single Rollerball. One direct impact can soften it up enough for the player to finish it off with one blast from the Double Shotgun.
- Large groups of Rollerballs can be decimated with either the XM214-A Minigun or the SBC Cannon. With the cannon, charged up shots work best.
- With other enemies, the Rollerball should be one of the first targeted enemies. It can sneak up on the player and do damage if the player isn't paying attention to it.
- Rollerballs are quite similar to the Rollermine from Half Life 2, in both design and behavior, though Rollermines are less spherical in shape compared to the Rollerball (they look more like soccer balls), and emit an electric charge when they touch the player.