The Archmage wizard gets a flat +10 bonus to her Spell Casting Skill. She also improves her Spell Casting Skill 50% more efficiently than other Wizards. Furthermore, her Enchantments are twice as difficult to dispel as those of a non-Archmage Wizard.
The term Archmage is an honorary title bestowed to those Wizards who have spent their entire lives studying and mastering the use of magic in all its many forms, and particularly the strongest spells present in the lands of Master of Magic. The Archmage strives to become the best spell-caster around, and is concerned entirely with the practical applications of magical energy - no theoretical nonsense.
Archmages will seek whatever methods they can find to make spell-casting itself seem easier and effortless. As their efforts reach their pinnacle, Archmages will be able to cast simple spells as an afterthought, and will seem to spent remarkably little effort even on the casting of powerful, earth-shattering spells. They use this advantage to overwhelm their opponents with complex series of spells, cast one after the other, until the enemy is subdued.
As a side-effect of this mastery of casting skill, the spells created by Archmages have a much stronger anchor in reality. A spell constructed so skillfully out of magical energy can be exceptionally difficult to get rid of.
Flat Spell Casting Skill Bonus
The first benefit given to the Archmage is a flat +10 bonus to the his or her Spell Casting Skill. This bonus is applied as soon as the game begins, and cannot be removed in any way.
This increased Spell Casting Skill allows the Wizard faster and more frequent overland spell casting, and increased use of spells during Combat.
This bonus is disregarded for purposes of calculating how many "Spell Skill Improvement Points" are needed to get to the next Spell Casting Skill level. For example, an Archmage at 20 Spell Casting Skill needs the same number of Improvement Points to go up one level that a regular wizard with 10 Spell Casting Skill would need. This prevents the Archmage's bonus from slowing down their improvement rate.
Faster Spell Skill Improvement
The second benefit applies to the speed at which the Archmage improves her Spell Casting Skill during the game.
When an Archmage invests any Power into improving his or her Spell Casting Skill, they enjoy a better conversion ratio. Instead of gaining one Spell Casting Skill Improvement Point per every Power Point invested, the Archmage gains 1.5 Improvement Point. The total number of Improvement Points gained per turn is rounded down to the next whole number.
For example, if a regular Wizard spends 10 Power per turn to improve her Spell Casting Skill, she will receive 10 Improvement Points per turn. An Archmage investing the same amount of Power would receive 15 Improvement Points per turn. She therefore gains Spell Skill levels at a 50% faster rate.
This allows the Archmage to quickly improve her Spell Casting Skill, the ability to cast spells rapidly or more often than other Wizards.
Alternatively, an Archmage may decide to improve his Spell Casting Skill at the same rate as other wizards. Since his efficiency ratio is better than that of a regular wizard, he only needs to spend 67% as much Power to keep up with his rivals in this field. This frees up a large amount of Power for Mana generation and/or Research.
Enchantments and Curses Harder to Dispel
The third benefit relates to the difficulty of dispelling the Archmage's Enchantments and Curses.
When an enemy Wizard casts a dispel type spell (Dispel Magic, Disenchant Area, Disjunction, or their "True" versions) on a spell owned by the Archmage, the chance of the spell being successfully dispelled is reduced.
Although the description implies that these spells become "twice as hard to dispel", this is generally not the case in practice. The basic formula for Dispel Magic type spells is:
Dispel Chance = ( Dispel Mana ) / ( Dispel Mana + Enchantment Mana ) * 100%
The Archmage Retort modifies this formula by doubling the spell's Casting Cost for the purpose of this calculation, which results in the formula:
Dispel Chance = ( Dispel Mana ) / ( Dispel Mana + 2*Enchantment Mana ) * 100%
Dispel Chance = ( 200 ) / ( 200 + 200 ) * 100% = 50%
Dispel Chance = ( 200 ) / ( 200 + 400 ) * 100% = 33.33%
This effect also stacks (additively) with the similar effect granted by realm masteries (Chaos Mastery, Nature Mastery, Sorcery Mastery). In this case, the Casting Cost of the spells belonging to the respective realms are tripled for the dispel calculation:
Dispel Chance = ( Dispel Mana ) / ( Dispel Mana + 3*Enchantment Mana ) * 100%
A maximum strength Disenchant Area spell ( 250) trying to dispel a Flying Fortress cast by a Sorcery Master Archmage Wizard ( 3 * 500 = 1,500 ) only has a 14% chance of succeeding. With only Archmage the chance would be 20%, and with neither Retort: 33.33%.
This rule applies to Enchantments and Curses of any type:
Cost and Requirements
The Archmage Retort is initially only available to wizards who possess at least 4 Spellbooks in any one Realm. A wizard may have any number of spellbooks from any number of colors, so long as at least 4 of them belong to the same color.
For example, a Wizard with 4 Spellbooks may pick the Archmage Retort, and then add any number and type of other books and retorts she can afford. Conversely, a Wizard with 3, 3 and 3 Spellbooks may not pick this Retort, since she does not have the required 4 books in any of the Realms she chose.
When creating a new Wizard, the Archmage Retort consumes only one pick.
The Archmage has an early spell-casting advantage: She can cast a higher ratio of spells per turn than other wizards, assuming she has sufficient Mana to do so. The advantage can be seen even more readily during combat, where an Archmage will be able to cast stronger spells early in the game.
Assuming the Archmage takes advantage of her Spell Casting Skill improvement speed, she will often end up with a much higher Spell Casting Skill than her rivals. In the later game, this will make it much easier for her to cast extremely powerful spells within a reasonably short number of turns. The Spell of Mastery may be a worthy goal to pursue, as it will take significantly less time to cast with such a high Spell Casting Skill. Global Enchantments, particularly the Very Rare ones, are highly recommended (particularly since the opposition will have such a hard time dispelling them).
Archmages also excel in combat spellcasting, as they can often cast far more spells than the opponent (or, alternatively, much stronger spells). Combat Enchantments, and even impromptu Unit Enchantments, can be a good bet as they cannot be so easily dispelled.