> ## Documentation Index > Fetch the complete documentation index at: https://docs.leapter.com/llms.txt > Use this file to discover all available pages before exploring further. # Decision Tables > Express first-match business rules as a grid of inputs and outcomes — clearer and easier to review than a long chain of nested decisions. A **decision table** captures a set of rules as a grid: a few input columns, one or more output columns, and one row per rule. When some inputs match a row, that row's outputs are produced. It is the natural way to express a lookup — "these inputs lead to this outcome" — where a long chain of [Decision](/elements/controlling-the-flow#decision) branches would hide the structure. Because the rules sit in a table, the inputs, the outcomes, and the order they are checked are all visible at a glance — which makes a decision table much easier for a reviewer to read and verify than nested IF/ELSE logic. ## Where decision tables appear A decision table is a type of element inside a Blueprint, shown as a grid with a table icon in the Blueprint's diagram — both in the [Specification view](/editor/specification-view) and in the [Diagram view](/editor/diagram-view). A maximized decision table from the Loan Application Scorecard — Map risk category and credit history to a decision, with the input columns riskCategory and hasCleanCreditHistory, the output columns decision and reviewAction, five rules, and the row ruler open on rule 2 ## How to read a decision table | Part | Meaning | | :- | :- | | **Input columns** | The values a rule looks at (left of the arrow marker) | | **Output columns** | The values a matching rule produces (right of the arrow marker `→`) | | **Rows** | One rule each, checked from top to bottom | | **`any`** | A wildcard cell — this rule does not care about that input's value | | **First-match** | The **first** row whose inputs all match wins; no later row is considered | The **F** in the table's top-left corner stands for **first match** and is a reminder that order matters: rules are evaluated top to bottom, and evaluation stops at the first row that matches. A row full of `any` at the bottom is a common way to provide a catch-all default. An input cell matches when the input **equals** the cell's value (for example a value of a [Choice Type](/editor/type-definitions#choice-type) or a boolean), or when the cell is **`any`**. Output cells are expressions, so an outcome can be a fixed value or a small calculation. ## Creating a decision table The quickest way to add a decision table is to ask the **[Lab Agent](/editing/lab-agent)**. Describe the rule as a mapping — for example *"map the risk category and the credit history to a decision"* — and the agent builds the table for you. When a rule is a straightforward lookup, the agent prefers a decision table over a chain of decisions. To add one yourself, click a connection point in the diagram and choose **Create a decision table** in the [element palette](/elements/controlling-the-flow). ## Editing a decision table **Edit a cell** by clicking it and typing a new value, or switch it to or from **`any`**. You can do this directly in the diagram or on the maximized table. To change the table's shape, **maximize** it: click its maximize icon to open the full-width view. Rulers above the columns and next to the rows hold the structural actions: | Ruler | Actions | | :- | :- | | **Row** (next to each rule) | **Add rule above**, **Add rule below**, **Delete rule** | | **Column** (above each condition or result) | **Add condition before** / **after**, **Add result before** / **after**, **Remove condition** / **Remove result** | To rename a column, click its header and type the new name. Edits go through the same save path as any other change, so they appear in the [Timeline](/track-changes/timeline), can be undone, and show up in review just like edits to any other element. ## Running a decision table When you [run your Blueprint](/test-and-validate/test-your-blueprint), the row that fired lights up in the table, so you can see exactly which rule applied for a given set of inputs. This makes it easy to confirm that the right rule won — especially useful when several rows could plausibly match and first-match order decides between them. ## What to do next * **[Controlling the Flow](/elements/controlling-the-flow)** — the other elements that make up a Blueprint * **[Lab Agent](/editing/lab-agent)** — build and edit decision tables by describing the rules * **[Test your Blueprint](/test-and-validate/test-your-blueprint)** — run your logic and see which row fires This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.