Guards are NPCs that protect cities, towns and outposts, and patrol some roads. They will attack nearby enemy players regardless of if they are flagged for PvP or not. Fighting back, or damaging them with spells like Thorns or Retribution Aura will flag their targets for PvP. Killing Guards gives no honor.
Guards will also attack nearby hostile monsters; a player who is unable to fight a monster (ie. because of level, out of ammo, weapon broken, etc.) can run to a nearby guard for protection, though they will recieve little to no XP if a guard kills the monster. This can sometimes be troublesome; nearby guards will attack and kill monsters, even those which players are not having trouble with, thereby robbing them of XP and loot for no reason. It is recommended that while leveling in a starting area, you do not fight near guards who you may inadvertently bring in to "save" you.
Approaching enemy NPCs will make them call out for help, spawning a few additional guards and sending a "<zone> is under attack!" message for the opposing faction's LocalDefense and WorldDefense channels. These spawned guards will disappear after a few minutes.
Each Alliance and Horde capital city has level 75 non-elite guards who offer directions to various locations of note within the city, including Class and Profession trainers. In addition, all capital cities except the Exodar and Silvermoon City have three elite guards who patrol every part of the city. They are able to see through Stealth and will throw a net that stops their targets for a few seconds. This is not a stun; snared targets are able to attack, but not move.
Predictably, every city, town, and outpost is guarded by members of the race it belongs to, except for the Undercity, which is being occupied and monitored by Thrall's Kor'kron Guard to prevent a repeat of the events of the Wrathgate.
For the most part, guards do little more than a basic melee attack. However, there are a few guards with special abilities to watch out for:
- Ironforge Guards use Thunderclap, slowing all nearby targets. This is arguably the most powerful ability used by guards in any city; the slow is typically all it takes for defenders to catch up to a nearby group of attackers.
- The few Undead guards who remain in the Undercity after the events of the Wrathgate retain their Plague Cloud, a passive damage over time to all nearby targets.
- Orgrimmar Grunts go into a frenzy when their health is low.
- Most guards are really no match for even poorly geared level 80 players, even the elite guards in cities. Their only real usefulness is that they will alert players that a city or town is under attack when they aggro.
- When asked for directions to class or profession trainers, some guards may respond differently depending on the stigma associated with certain classes and professions among their race. For example, the usually jovial Ironforge Guards will respond unkindly when asked for directions to a Warlock trainer, and the Silvermoon City Guardians will sneer at Hunters.
- Guards that are automatically spawned when a city or zone is under attack do not offer directions. This is useful when trying to find out where attackers in a city or zone are: if you mouse over a guard and your cursor does not change, this is a telltale sign that they are nearby.
- Ironforge and Silvermoon City guards are all male. Darnassus Sentinels are all female.
- Silvermoon City Guardians have a completely different model than the one used by other Blood Elf NPCs and playable Blood Elfs, resembling Spell Breakers seen in Warcraft III: The Frozen Throne. They also have unique aggro and death sounds.
- Dalaran has no guards; directions are instead given by local mages. The Underbelly has its own set of directions.