# The Deterministic-First Cascade
Source: https://humanspark.ai/frameworks/deterministic-first-cascade/

*Run cheap predictable rules first; hand only the exceptions to the AI.*

**When to use:** Designing an AI pipeline that stays cheap and predictable at volume.

Rules first. *AI* for the exceptions.

A deterministic-first cascade: cheap, predictable rules handle the bulk, and the LLM only catches what the rules miss.

> **The trap:** Treating the rules as decoration. In a cascade the rules do the bulk of the work; the model only catches what they miss.

> **Not to be confused with:** Not [Rules Before Guesses](https://humanspark.ai/frameworks/rules-before-guesses/): that card chooses between a rule and AI for a task; the cascade puts both in one pipeline - rules first, the model as the catch.