When armies stay motionless on the world map for a certain amount of time (one turn for Napoleon: Total War and two for Empire: Total War) and is attacked, certain units gain the ability to place useful objects on the field before a battle commences. Fougasse is one such deployment option, a primitive landmine set to explode when hostile units wander within its trigger zone. Fougasse is available to most forms of light infantry and some skirmishers, but rarely to irregular troops. The trigger zone is depicted on the battlefield as a red bloom (this bloom is visible to the opposing player in Napoleon: Total War but not Empire: Total War). The fougasse itself appears as a small rectangular box on the battlefield. When triggered, the fougasse explodes, sending a shower of debris in the direction of hostile units. It is most deadly at point blank range, though it usually activates at maximum distance, inflicting moderate-high casualties.
Fougasse is most deadly when placed in chokepoints, where hostile troops have a chance of concentrating.
Fougasse does not trigger near friendly units (allied or player controlled), though it can still cause friendly casualties if they are too close when the fougasse is triggered. It deals minimal damage to buildings. It can work as a form of flank protection, though its one-time usage means that it is less effective in this role than Chevaux de Frise or Earthworks. When used primarily to kill and impact morale, it works best when placed within range of missile troops. This way, the explosion of fougasse can be coordinated with a hail of musket fire or other ordnance, and the cumulative effect on morale and troop numbers can be devastating.
In Empire: Total War, if troops are able to place fougasse but aren't made to do so in the deployment phase, they place the fougasse randomly in the deployment zone before battle commences. Fougasse placed in such a manner is nearly identical to manually placed fougasse, with the exception of the red bloom being invisible to the player.
In Empire: Total War, most skirmishers and some irregulars have the ability to deploy improved fougasse. Like fougasse, it acts similarly to a conventional mine, exploding and sending a shower of debris in the direction of hostile units if triggered. Improved Fougasse launches a shower of grenades in addition to the debris, causing a secondary explosion and creating additional casualties after the initial explosion.
Improved Fougasse is absent from subsequent Total War iterations, although it is listed in game files for Napoleon: Total War.