Diplomacy

Secondary skills
Air Magic
Archery
Armorer
Artillery
Ballistics
Diplomacy
Eagle Eye
Earth Magic
Estates
Fire Magic
First Aid
Intelligence
Interference
Leadership
Learning
Logistics
Luck
Mysticism
Navigation
Necromancy
Offense
Pathfinding
Resistance
Scholar
Scouting
Sorcery
Tactics
Water Magic
Wisdom

Diplomacy
	Basic Diplomacy: allows you to negotiate with monsters who are weaker than your group, and reduces the cost of surrendering by 20%.
	Advanced Diplomacy: allows you to negotiate with monsters who are weaker than your group, and reduces the cost of surrendering by 40%.
	Expert Diplomacy: allows you to negotiate with monsters who are weaker than your group, and reduces the cost of surrendering by 60%.

Description

Diplomacy reduces the cost of surrendering, and increases the chance of wandering monsters joining you, be it for free or at a price. Also, whereas heroes may normally enter a Library of Enlightenment only when having reached level 10, basic diplomacy enables heroes to enter at level 8, advanced diplomacy at level 6, and expert diplomacy at level 4.

Recommended for: At least one hero, typically a support, on maps with wandering monsters that are not set to 'savage', but preferably to aggressive (i.e., the default setting, see below).

There is no need for your main hero to learn this skill. Troops from your main hero can simply be transferred to a support hero skilled in diplomacy, who can then convince the wandering monsters to join and subsequently return the troops. This saves your main hero a skill slot and potentially a lot of movement points.

The Diplomacy skill is often regarded as overpowered by tournament players, and therefore frequently banned from competitive play.

Wandering Monsters

Whether wandering monsters join you or not also depends on the formation of your army. Your army belongs to one of the three groups:

a. has none of that kind of monster at all. 
b. has at least one of that kind of monster
c. the number of that kind of monster in your army is strictly above 50%.

Case C has the best odds of the monsters joining. In all three cases, both upgraded or non-upgraded are counted.

Comments

Works very well with Visions, and can easily be the skill that wins the game for you.

It goes without saying, but Diplomacy is especially useful to players who like racking up wandering monsters that match their armies. Cunning Necropolis heroes that somehow learned Diplomacy can also exploit it for free Skeletons (which is more efficient than fighting for them).

Heroes

Heroes that start with Diplomacy: Adela, Cyra, and Ryland.

External links

• Thread on HeroesCommunity, started by AlexSpl: Diplomacy internals