843 Skill Trees

An in-progress dissection of skill trees:

Primary Types

Compound Skill Trees:

A compound skill tree is the most common type found in games. It’s defined by a single or very small number of base nodes, each descending down it’s own branching “tree” of nodes. The defining characteristic of this type is that there are decision splits at some or every junction.

Linear Skill Trees:

A linear skill tree doesn’t necessarily always look like a tree, but can. It’s classified by a general lack of choice. As in, it’s typically a linear path from start to finish, and all that makes it functional is the rate and method the player must use to unlock each successive node.



A node is an individual point on the tree. To be considered a tree, it should probably contain at minimum two, but hopefully at least 3. A base node is the starting point of a branch.


A collection of nodes.

Decision Splits:

An aspect of a branch, when a linear collection of nodes is broken up by a decision point. Can be restrictive or open.


A compound tree can be stylized as a centralized tree, as can a linear tree. Typically, these start with a single node in the center of a web of expanding choices. The player often needs to choose a single direction to proceed in, and if decides to move in a different direction, has to start first at the centralized node.


A restrictive skill tree prevents the player from choosing a certain option or options if they choose a different one, often at the same “tier” level.

Node Progression:

An aspect of a single node of a skill tree, defining whether or not the player activates the node only once, or can add to it incrementally, often independent of any other node on the tree.

Node Dependency:

Most often, a node that’s below another one is dependent on the activation of that upper node to unlock it. Sometimes there are other dependencies or requirements in other parts of the tree that allow or restrict the player progressing in a certain direction or at a certain rate.


Tiers are used to classify and group nodes (e.g. horizontally in a descending tree, or in zones for a centralized tree). The nodes are often grouped by accessibility, requirement, or some other similar trait. Occasionally it is arbitrary.

[ Today I Was Playing: nothing… ]

April 23, 2017

#game-design-topic, #game-mechanic-system