Skill Tree

Skill Tree is a progression structure where earned points buy nodes on a branching graph of abilities, and the branching is the entire point — a flat "level up, get bigger numbers" system communicates growth, but a skill tree communicates choice, because most trees make some nodes mutually exclusive or gate later branches behind earlier ones, so which path a player commits to actually forecloses others. Path of Exile's tree is the genre's most extreme expression: hundreds of nodes across a sprawling web, deliberately overwhelming, where the game's real character-building happens entirely outside combat, in planning the path itself.

The interesting failure mode is a tree that only looks branching. If theorycrafting settles quickly on one dominant path — a "wet noodle" tree, where every alternate branch is strictly worse — the tree is decoration laid over what functions as a linear unlock list, and the appearance of choice was never backed by a real one. This is where Metagame does its damage: a community-solved "correct" build collapses a tree's apparent width back down to a single line the moment enough players compare notes, and a tree only stays meaningfully branching if its build space resists being solved, or if the designers keep rebalancing to break up whatever solution calcified last patch.

Respec systems — letting a player refund points and rebuild from scratch — exist as the safety valve for build regret, and their presence or absence is itself a design statement: a game with no respec is betting that commitment to a build matters enough to be worth the risk of a wasted early choice, while a game with cheap, frequent respec is treating the tree as a tuning dial rather than a real decision.