Pledging

“	Here do I swear fealty and service to Gondor, and to the Lord and Steward of the realm, to speak and to be silent, to do and to let be, to come and to go, in need or plenty, in peace or war, in living or dying, from this hour henceforth, until my lord release me, or death take me, or the world end.	”
–-The Return of the King, Minas Tirith

Pledging is a gameplay mechanic added to the mod in Update 35. Here, the player swears allegiance to a faction of their choice and gets certain benefits for this. You can only be pledged to one faction at a time.

Pledge Service

To be able to pledge, make sure that you are not already pledged to another faction. Otherwise cancel that pledge first (see below). Then, you'll need to get at least +100.0 alignment to the faction of your choice. You can either do mini-quests for them,or kill their enemies in their Area of Influence. Then open the Middle-earth menu (normally pressing "L"), select the factions button or press "F", and scroll over to the desired faction.

Pledging possible, seal displayed in red

On the first page of the respective faction, you'll find a red seal in the lower-left corner. This seal is greyed out if you don't have the necessary alignment; otherwise, you are able to push it.

After pushing the seal, you may get an error message, that it is not possible to maintain good relations with the faction's mortal enemies. In this case, both alignments will be reduced until one of them reaches zero (this can be turned off via the configuration file). This may also reduce your alignment to the desired faction below the needed +100.0, meaning that you need to work towards increasing it again. It's also possible, that you need to wait for a cooldown from a previous pledge to subside.

Pledging possible, final confirmation page

After successfully pushing the seal, you will get a final confirmation page. Hitting the red seal on this page signifies your allegiance to that faction. You will hear a fanfare play to celebrate your pledge.

Doing this for the first time will earn you the achievement "Here Do I Swear". The first page of the respective faction displays "pledged". The seal now allows you to cancel the treaty.

Benefits

Higher ranks of the pledged faction become available for the player (including the respective achievements).
Some hired units are only available for pledged players.
Captains sell their units to you much cheaper (if at all).
Players are able to conquest for their faction.

Breaking the Pledge

Breaking the pledge can happen in three ways:

kill a NPC from the pledged or an allied faction
lose too much alignment to the pledged faction
break the treaty willingly

If you kill an allied NPC, you'll get the warning to the left. If you kill another one within a certain cooldown time, your faction loses faith in you.

If your alignment to your pledged faction sinks below the threshold of +100.0, the faction will cancel the treaty. This can happen by performing evil deeds (in the eyes of your faction) or by gaining positive alignment to their mortal enemies with the alignment-drain option "on".

Breaking the seal, final confirmation page

You may want to break the pledge willingly, despite having enough alignment. Open the Middle-earth menu (normally by pressing "L"), select the factions button, and scroll over to the desired faction. Now push the red seal. The picture changes to a broken one. After a final confirmation page, the contract will be broken and a sad fanfare announces this.

You'll get the chat message to the left when you break the pledge yourself.

Penalties

Either way you break it, you'll recieve the following penalties:

Depending on your previous alignment, you'll lose between 50 (at +100.0) and 90 (!) (at +10,000.0) percent of your alignment to the respective faction.
The pledge cooldown will be set to quite a certain amount of time, in which you are not able to pledge to another (or the same) faction.

The following command can be used to set the cooldown time: