A Landmine is an explosive that appears in Halo: Reach, Halo 4, and Halo 2: Anniversary. While Landmines may be placed in Forge Mode, they also appear in matchmaking when the Race gametype is voted for. They also appear in Breakpoint. It functions similar to that of the trip mine; a usable piece of equipment in Halo 3. While the flashing red light atop the mine is quite visible, it can still catch unwary drivers off guard. Many "Forgers" often turn Landmines upside down and through the ground using the "Phased" setting, making an almost invisible and effective trap. Unless custom settings are used, all vehicles will be destroyed if they are within the blast radius of the mine, in other words they are an instant kill to any vehicle with the exception of the Scorpion, which requires at least two.
- Landmines can be activated by proximity. If you drive or walk close enough to one, they will explode after a short delay. This can be used to stop any player following close behind you.
- The Landmine is the most sensitive explosive in Halo: Reach. Even a slow-rolling Frag Grenade will detonate it.
- In the Race gametype, Landmines will often have barely visible waypoints above them alerting you of their presence.
- You cannot stack Landmines - contact with any other object causes instant detonation.
- The landmine will not appear to the viewer if they are a minor distance away. As the player backs away from one it will fade from visibility to create a buried effect.
- Holding a vehicle over one in monitor mode will cause it to explode, usually not destroying it, but blowing the turret off of said vehicle. Warthogs look similar to their civilian version, scorpion turrets will be completely blown off. Wraith mortar cannons will fall off and the same will happen to the Revenant. You cannot shoot or enter the gunner seats of the vehicles once you have done this, making the only way to actually kill someone via a splatter. Note: That this can also happen in matchmaking to Wraiths if they survive a hit from a Scorpion.
- A particularly nasty trick is to place Landmines stuck to a wall with the Fixed option in a choke point and shoot it as someone passes by. The explosion in such a small area is a confirmed kill and if it is placed around a corner the person may not even see it.
- If a Landmine is placed in the air using the Fixed option upside down, you are able to stand on it.
- If you set weapons and melee damage to 0%, you can stand on and push landmines around (not in forge).