Every class is built around this core loop: generate **resource**, then spend it on core skills. A Barbarian builds Fury through basic attacks or shouts, then unleashes it on devastating Hammer of the Ancients or Whirlwind casts. A Sorcerer regenerates Mana over time and through specific skills, spending it to cast devastating Chain Lightning or Ice Shards. How a player manages this flow is paramount. Spamming core skills too quickly leads to **resource** starvation, creating dangerous downtime. Being too conservative wastes potential damage output. The balance is further complicated by legendary aspects and passives that alter the equation. An aspect might make a skill generate **resource** under certain conditions, or reduce its cost after a critical hit. Talents on the skill tree and nodes on the **Paragon Board** are dedicated to increasing maximum **resource**, improving generation rates, or adding effects that trigger on **resource** expenditure.