Spider Mines are placed on the ground by Vultures. Once deployed, the mine burrows into the ground rendering it invisible and then anticipates a target. (The mine will burrow even if a target is already in range when first placed.) When a unit comes into range, the mine unburrows and, after a brief delay, launches itself at the target far faster than most units can avoid. A player cannot manually order mines to move.
A Spider Mine will attack any hostile non-hovering ground unit that comes in range, even cloaked units. If the target becomes invalid due to the unit dying or being picked up by a transport, the mine will burrow again at its current location and acquire a new target.
- Destroying a mine does not deal any damage to nearby units, although its graphic is the same as when it detonates.
- Invisible units trigger Mines even if they are not detected.
- Mines do not receive armor upgrades.
- If a spider mine is blinded by a Medic's Optical Flare, it will not unburrow or explode unless a triggering unit is directly on top of it. (Disallows mine defusing with Dragoons or Siege Tanks.)
- Disruption Web will temporarily disable all spider mines underneath the affected area for the duration of the spell.
- Defensive Matrix, Hallucination and Parasite may be cast on spider mines, and will be effective. Hallucinated spider mines trigger as normal, and deal no damage.
- SCVs and Medics cannot repair or heal damaged spider mines.
- Mind Control, Lockdown, Spawn Broodling and Maelstrom are ineffective against spider mines.
- Irradiate, Ensnare, Plague, Stasis Field, Recall can only affect unburrowed spider mines. If a spider mine is underground when one of the above spells is cast, it will be unaffected. Recalled spider mines will automatically burrow at the new site.
- Spider Mines will target Zerg larvae and eggs. The explosion does not harm the hatchery/lair/hive, but the splash may be used to kill nearby drones.
- Unburrowed spider mines can be cloaked by an arbiter.
- Spider Mines should be placed in a tight line against units with a high rate of fire. This is so more Spider Mines will be triggered and hit the enemy units.