Horde

A Horde is a random event in which the Heroes are swarmed by enemy Infantry. Hordes are triggered by a hidden timer and occur in every mission. Large groups of enemies spawned during mission events are also often called hordes.

General
Hordes consist of a great number of low-risk Infantry and spawn throughout every mission. The difficulty level determines the exact amount of enemies during a horde, which can run up to hundreds on Legend. As hordes are triggered by a timer, it is a mechanic that encourages parties to keep moving and creates a risk-reward system for exploring the map and finding consumables and books. Knowing the "ins and outs" of hordes is vital for surviving missions, especially on higher difficulties.

At the start of a horde event, a sound queue is played which lets the party know what type of horde is coming and from what side (front or back) the first wave of enemies appears. Hordes always spawn in three waves: each wave will spawn in short succession of the previous wave and either on the same or the other side as the last wave. An exception is the ambush (see below).

During most events the horde timer is ignored, as these events often have scripted hordes instead. However, the timer does keep running, and hordes often spawn immediately after an event is completed.

Skaven
A Skaven horde exists only of Skavenslaves. Though these are the weakest enemies in the game, they make up for this by sheer numbers, as during a horde up to hundreds of Slaves can spawn on Legend difficulty. As their power lies purely in numbers, creating a bottleneck and having melee weapons with high cleave is especially useful for dealing with these hordes.

Ambush
Through their extensive tunneling systems, Skaven are able to surround and ambush the players. An ambush is a special type of horde-event, in which Skaven Slaves pop up on every side of the party through cracks and crevices found throughout every mission. This makes creating a bottleneck difficult and this type of horde very dangerous for unprepared parties, as the Skaven spawn close to the players and can even spawn in between the party. The "three-wave rule" doesn't apply for this event. Instead, a single wave spawns in a longer stretch of time.

Rotbloods
A Rotblood horde is made up mainly of Fanatics with some Raiders and Bulwarks included. The number of enemies per wave is low compared to Skaven hordes, but as the amount of health for Rotblood unit is significantly higher, these waves are a lot more bulky: high-damage weaponry is more suitable for dealing with this type of horde. Be aware of the Bullwarks, as the presence of their shields can make cleaving impossible; try taking them out first. In wide open areas it might actually better to spread out and thin their numbers instead of trying to find a bottleneck.

Strategy

 * Listen carefully, not only will the initial sound queue of a horde tell you which type of horde spawns, it also indicates from which side (front or back) the first wave will come from. Using headphones with good stereo-sound will help with recognizing a horde and responding accordingly.
 * When a horde triggers (especially Skaven hordes), immediately look for bottlenecks the party can use to minimize the risk of being swarmed from every side. Be sure to keep an eye on your party members and if possible communicate about where you go, as stragglers are especially vulnerable.
 * As hordes will aggro any enemy already spawned in front of the party (except patrols), try and kill any visible elites before the first wave of the horde arrives. Otherwise these Elites will come simultaneously with the first wave and greatly increase the difficulty of the horde.
 * A well placed bomb or blown up keg can instantly kill a single wave.
 * Some ranged weapons are very potent in horde clearing. Sienna's Flamestorm Staff, and Bardin's Grudge-Raker and Drakegun allow them to singularly hold of a horde, even on Legend difficulty.
 * Keep in mind specials keep spawning during a horde. Keep prioritizing disablers, and remember that Globadiers, Warpfire Throwers and Ratling Gunners can actually help to clear a horde with friendly fire.
 * Though it is possible to keep progressing the mission during a horde, it is not advised to do so. Monsters and patrols can still spawn during hordes and will increase the difficulty as the party will need to deal with them simultaneously.