There are three types of special Uruks-Captains, Bodyguards, and Warchiefs. Common to all three of these types are Uruks is a set of randomly determined Strengths and Weaknesses (which cannot be exploited without gaining Intel) and Power Rating. These Uruks glow red when seen via Wraith Vision, drop Runes and reward Power when killed. Like lesser Uruks, they are either Warriors, Archers, Hunters, Defenders or Berserkers, with the same weapons and attacks… plus perhaps extra abilities, depending on their Strengths.
An Uruk’s Power Rating is more or less their level-the higher the Power Rating, the more powerful the Uruk. Uruks with a higher Power Rating tend to have more traits, generally favoring Strengths over Weaknesses. Uruks can gain Power by killing the protagonist, getting promoted, or successfully completing Power Struggles. Sending an Uruk a Death Threat will also increase their Power Rating by five, making it the easiest way to significantly increase an Uruk’s Power Rating. Power Rating can vary between one and twenty.
When you kill an Uruk, you’ll gain Power equal to the Uruk’s Power Rating. Runes dropped by Uruks also have a base level equal to the slain Uruk’s Power Rating (except for Epic Runes, which have no level).
The most common of the more powerful Uruks, Captains can vary greatly in Power and can be found lurking around Mordor. Occassionally they have retinues of Uruks that are often the same type (Hunter Captains will have Hunters in their retinue). Captains commonly engage in Power Struggles, which if successful will increase their Power. A lesser Uruk who kills the player will become a Captain, but otherwise Captains are regularly promoted as time goes on. Captains will almost always drop normal Runes when killed, but a Captain who recieves a Death Threat has a 40% chance to drop an Epic Rune. After receiving a Death Threat, the Captain will gain five Power and a retinue of followers of the same type. A Branded Captain can be Commanded to join a Warchief, and if they succeed at a Power Struggle, they will become a Bodyguard.
Bodyguards are Captains who serve a Warchief. When the Warchief is summoned, they will be part of the Warchief’s retinue. Otherwise, they can be found throughout Mordor like normal Captains. All Captains are not Bodyguards, but all Bodyguards are Captains.
The strongest of all Uruks, Warchiefs can have a retinue of Bodyguards. Unlike Captains, they cannot be found wandering Mordor, they must be successfully challenged by completing a random Showdown Mission. This must be done each time a Warchief is encountered. Warchiefs commonly drop Epic Runes (almost guaranteed if they are the recipient of a Death Threat), and must always be finished off with a button prompt. There are only five Warchiefs at any one time in either Nurn or Udun.