A zerg is a large, loosely organized group of players with the goal of completing a task or series of tasks. The commander mechanic provides a leader to organize and focus a zerg on tasks. Zergs are common in World versus World, which is designed for large groups of players. Zergs are also common in PvE for large scale events such as world bosses and farming.
Zergs can form spontaneously for any activity where a large number of players are present and a specific task is given. This task can be designated by the game, such as taking a keep or supply camp in World versus World or a dynamic event in PvE. It can also be formed by a player or group of players, typically a guild.
Zergs are typically started by players with the commander icon. This visible icon serves as a focal point for unorganized players on the map, who tend to congregate towards the commander.
When a zerg faces strong opposition, it will often break up, with people retreating to all directions and losing touch with the rest of the players forming the zerg. Alternatively, when a zerg successfully captures an objective, it is possible for people to start running in different directions, forcing others to choose between the two. This can split a large force into smaller ones, which will be more easily defeated by defenders and truly dissolved.
World versus World
In World versus World, the commander can direct a large number of followers (the zerg) towards objectives he or she wants to attack or defend. Since outnumbering the opponent greatly increases the chances of winning encounters in World versus World, zergs usually form as soon as a side's map population rises. Zergs number anywhere from 15-25+ players. Large zergs can comprise most of the map population and can include well over 50 players and those are general referred to as blobs. If led by a commander, the effectiveness of the zerg largely depends on the leadership of the commander, who determines the movements of the zerg.
If two especially large zergs meet in a fight, the sheer number of players interacting can cause the game to partially freeze. One very notable effect is skills not activating upon hitting their button. Buffs and debuffs can also last considerably longer than usual. After the fight is over, skill lag is sometimes followed by a period of sped-up gameplay. During this phase, players may attack much faster then usual. Skill lag from big fights usually occurs during large-scale fights over important objectives, like Stonemist Castle or a server's home, like Garrison keep.
- Primary article: Champion farm
Zergs are also prolific in PvE, though function differently. While large groups of players will show up to kill world bosses, they usually go their separate ways after the boss is killed, and therefore cannot really be called zergs. Instead, PvE zergs focus on champion farming, where players group together and follow a set pattern to kill champions in a set order to quickly acquire champion loot bags.
- The term Zerg Rush originates from the RTS Starcraft, where one side, the Zerg, specialised in using many weak units to outnumber and swarm a more powerful opponent's army, a parallel easily drawn with WvW where many people swarm the fortified position of a Tower or Keep.