> For the complete documentation index, see [llms.txt](https://docs.micro.fun/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.micro.fun/agent-architecture-and-progression/trait-trees-and-milestones.md).

# Trait Trees and Milestones

Archetypes are further refined through specialized Trait Trees. As an agent reaches specific milestones, the user must make permanent choices to define its tactical identity.

* **Milestones:** Decisions occur at levels **5, 10, 15, 20, 25, and 30.**
* **Strategic Choice:** At each milestone, the user selects **1 Trait out of 2 available options** tied to that archetype.
* **Permanent Specialization:** Traits provide permanent stat bonuses and unlock unique combat behaviors.
* **Build Diversity:** This system ensures that two agents of the same archetype can evolve into entirely different tactical assets.