The Arc Mine is a proximity mine that can stick on any surface. It takes 1 second after sticking to something to arm. Arc Mines won't explode until an enemy Pilot, Titan, Grunt, or Spectre enter the mine's range. Once activated, it starts beeping rapidly for 0.7 seconds, then detonates and releases a powerful blast of electricity, dealing damage and distorting the vision of enemy Pilots and Titans for a short period of time (similar to the Arc Grenade.)
Planting one behind you (but not too close!) can protect you while sniping; would-be stealthy executioners are disoriented by the detonation and easily finished off with your sidearm.
The blast from an Arc Mine is sufficient to kill a minion, and when placed in a common lane, can eliminate an entire squad for Attrition points and/or to advance your Titanfall cooldown.
They can be scattered around a flag, Hardpoint, or Harvester for limited protection or warning against enemy pilots or minions.
Arc Mines can be thrown like grenades, although not as far. They will heavily fall downward after throwing, so they can be used to clear rooftops while standing under the eave of the roof. Grenades are still significantly better at offensive engagements, and can be thrown much further.
In Hard Point, Arc Mines can be used as traps against incoming enemy Pilots or Titans who are coming to take the hard point. Placing Arc Mines near each other will ensure a kill should the Pilot walk through them.
While a powerful support weapon, Arc Mines are not very useful against Pilots; the low damage of an Arc Mine (relative to a Satchel Charge or Frag Grenade) means Pilots require two mines to kill, and Titanfall's parkour system makes it difficult to predict the route an enemy Pilot will take.
Arc Mines (and grenades) also affect you; if you are nearby when the mine detonates, it will distort your vision, too.