The bonus of the Warden gives +10% to the defense of the hero's creatures.
The Warden is most likely to learn Tactics and Nature Magic and fairly likely to learn the Combat and Scouting skills. Wardens can not learn Order Magic or Death Magic when leveling up unless some basic training in those skills is already known.
This is a useful bonus, essentially counting as another level in the Defense skill, which can be gained through Tactics.
|Heroes of Might and Magic IV classes|
|Standard hero classes||Knight - Death Knight - Lord - Thief - Archer - Barbarian - Priest - Necromancer - Mage - Sorcerer - Druid|
|Advanced classes||Archmage - Assassin - Bard - Battle mage - Beast lord - Beastmaster - Cardinal - Crusader - Dark Lord - Dark Priest - Demonologist - Enchanter - Field marshal - Fire diviner - Fireguard - General - Guildmaster - Heretic - Illusionist - Lich - Lord commander - Monk - Ninja - Paladin - Prophet - Pyromancer - Ranger - Reaver - Seer - Shadow mage - Summoner - Warden - Warlock - Warlord - Witch king - Wizard - Wizard King|