TR/9 trip mine/Gameplay

Tactics

 * The most important thing to note when deploying a Trip Mine is to inform your allies. Unwary teammates may activate your Mine, resulting in a betrayal.
 * In Campaign, you should destroy activated trip mines as you leave an area, as marines are scripted to run certain paths, and if an un-detonated trip mine is in the way, they may simply walk over it, killing as many as three or four of them.
 * When fleeing an enemy vehicle, it may be wise to deploy a Trip Mine in its path. Such a move may kill the occupants of the vehicle, though it also poses a risk to the player trying to flee.
 * A Trip Mine is a useful counter to a Bubble Shield. Throwing a mine into an occupied Bubble Shield will almost always result in its detonation, and the resulting blast will be contained within the shield, killing only its occupants. If the explosion destroys the shield generator, however, it may "escape" the shield.
 * If you deploy a Trip Mine on top of a Man Cannon, the mine will go flying out into the battlefield. In the Halo 3 Beta, the Trip Mine would sometimes disappear entirely when thrown into the Man Cannon. It would still explode if someone or something goes within the activation radius.
 * One of the most evil tricks, as Bungie has mentioned, is to deploy a mine in the exact position where it spawns. Some players will notice that the mine is armed, but many players will attempt to collect it, resulting in a kill (if the player's shield is almost depleted) which would certainly not have happened if the player was attentive. This tactic can easily result in a betrayal, however, so teammates should be warned.
 * Trip Mines can be used to block doors, hallways, sniper perches, and other areas.
 * If a player walks slow enough or crouch-walks over a Trip Mine, it will not explode.
 * A Trip Mine's beeping tends to reveal its presence, but by hiding it around a corner or over a ledge, a player can prevent the mine's orange glow from compounding the problem.
 * Throwing a Trip Mine underneath a vehicle will mask its glow, muffle its beeping, and turn the vehicle into a deathtrap.
 * In Capture the Flag, a player can place a Trip Mine by their own flag. It will kill any opponents that are trying to steal the flag. This tactic works very well when one flag gets the win; a good deal of players will be focused on getting the flag, so the Trip Mine would be ignored until it detonates.
 * In multiplayer, Banshees are commonly used to splatter enemies. If you happen to see a Banshee angling toward you and boosting, drop a Trip Mine. The explosion will probably kill both of you, but is usually still desirable, as Banshees are often hard to kill.
 * On Avalanche, slip a trip mine under the most valuable vehicle at the enemy base, since they know it is underneath one of the vehicles, they will most likely take the Scorpion, Type-26 Wraith or Hornet, resulting in severe damage or death.
 * If a player has low shields and an enemy is chasing him/her, a good tactic is to throw the Trip Mine down. If the attacker comes around the corner, the resulting explosion will deplete their shields, allowing the defender to finish them off with a headshot. If the attacker hears the beeping and stays back, the defender will have a chance for their shields to recharge.
 * If two players are in close combat and one is about to die, the losing player can deploy a Trip Mine right at the other player, as an act of vengeful suicide.
 * Try making Trip Mines land upside down by bouncing off a wall or solid object, because they are much harder to see, since the light is pointed into the floor/ground.