The seven hero classes in Guildrun
Every hero in Guildrun belongs to one of seven classes, and the class decides which stat carries them: Attack for Warriors, Defense for Tanks, Max HP for Vanguards, Crit for Assassins, Attack Speed for Duelists, Mana Regen for Mystics and Magic for Mages.
The class also decides what a rank up is worth. Ranking a hero gives 25% Max HP, 30 Defense, 25 Attack, 25 Magic, 20 Attack Speed, 15 Crit or 4 Mana Regen in the class primary stat, against half or less of that in every other stat.
Second classes in Guildrun
A hero can end up with two classes. Three heroes start that way, and twenty one specializations grant a second class when you choose them, which is how a Warrior ends a run also counting as a Duelist for every relic and rank up modifier that cares.