Catan Board Generator
v3.1.0Game
A fan-made tool that generates balanced starting boards for Catan. High-probability numbers and adjacent resources are distributed for fairer play.
Generating board...
App version available!
Hex Settlement Board Generator
iOS
Available on App Store. Generate boards in 3 modes: Fair, Normal, and Chaos. Supports statistics display and image saving.
Generate a Board in 3 Steps
1
Select Board Type
Choose Standard (3-4 players) or Expansion (5-6 players). You can also pick a balance mode: Fair, Normal, or Chaos.
2
Shuffle to Generate
Press the Shuffle button to generate a board. Resource tiles and numbers are automatically optimized. Regenerate as many times as you like.
3
Save Image and Play
Download the generated board as a high-quality PNG image. Save it to your phone or tablet and use it for your game.
Placement Rules Overview
This generator builds on the official rules and adds custom balancing adjustments for a fairer, more strategic game experience.
Basic Placement Rules
- No Adjacent Identical Resources: Same-type resource tiles (forest, pasture, etc.) are never placed next to each other.
- No Adjacent Specific Numbers: High-probability "6" and "8" and low-probability "2" and "12" are not placed adjacent to each other.
Advanced Balancing
- High-Probability Number Distribution: "6" and "8" are spread across different resource types so they don't concentrate on a single resource.
- Intersection Value Equalization: The value of "intersections" (where 3 tiles meet, summing each tile's probability) is checked so that extremely low-value clusters are avoided.
- Per-Resource Number Quality: Each resource is guaranteed at least one productive number (4, 5, 9, 10, etc.), and the total expected production for each resource stays above a minimum threshold (Standard: 11, Expansion: 16). This prevents any resource from being extremely unproductive.
Balance Disruption Options
- Resource Expected Value Balance: In "Fair" mode, each resource's production stays above a minimum threshold. In bias-heavy modes, extremely unproductive resources may appear.
- Resource Adjacency Restriction: When ON, identical resource tiles are never adjacent. When OFF, same resources may be placed side by side.
- Number Adjacency Restriction: When ON, high-probability (6-8) and low-probability (2-12) numbers are kept apart. When OFF, these restrictions are removed, producing more unbalanced boards.
About the Display
- Number Probability: The dots below each number chip show how likely that number is to be rolled (out of 36 possible outcomes).
- High-Probability Highlight: The most probable numbers, "6" and "8", are displayed in red.
Usage Notes
- This tool is designed for a fair game experience, but what makes a board "optimal" can vary depending on player strategy and preference. The generation logic includes probabilistic elements, so we recommend verifying the final board layout to your own satisfaction before playing.
v3.1.0(2025/12/04)
- Unify theme colors for site-wide consistency
- Redesign settings panel (rounded corners, borders, independent style)
- Add 3-step how-to cards
v3.0.0(2025/10/08)
- Major UI/UX overhaul: Unify to dark theme with modern tool layout
- Balance mode: Select game balance from 3 levels (Fair, Normal, Chaos)
v2.2.1(2025/06/25)
- Performance optimization: Reduce memory usage by ~50% with in-place Fisher-Yates algorithm
- Web Worker optimization: Send constant data only once on initialization, reducing communication overhead by ~30%
- Speed up calculations: Implement intersection value caching to reduce redundant calculations by up to 70%
- Improve rendering: Separate BoardTiles component and optimize with React.memo
- Overall performance improvement: Achieve 20-30% faster generation for standard and 40-50% for expansion boards
v2.2.0(2025/06/14)
- Add balance chaos option to intentionally allow resource and number bias
- Resource expected value balance: Adjust production expected value floor per resource with selectable bias level
- Resource adjacency restriction: Option to restrict same resources from being adjacent
- Number adjacency restriction: Option to restrict high/low probability numbers from being adjacent
v2.1.0(2025/06/12)
- Add statistics section showing resource production probability
- Set minimum total production expected value per resource (standard: 11, expansion: 16) for improved fairness
- Introduce Web Workers to speed up and stabilize board generation calculations
v2.0.0(2025/06/07)
- New feature: Add 5-6 player expansion board generation with button toggle between standard and expansion
- Logic improvement: Dynamically adjust fairness parameters (intersection expected value tolerance, search steps, etc.) for expansion tile count
- UI/UX improvement: Suppress screen flickering during board generation (shuffle) and display loading screen smoothly
v1.1.0(2025/05/08)
- Add rule preventing numbers 2 and 12 from being adjacent for improved fairness
- Introduce intersection expected value evaluation to prevent concentration of low-value intersections
- Add per-resource number quality check to prevent extremely low numbers from clustering on one resource type
- Improve board generation stability and optimize internal processing
v1.0.1
- Improve download image resolution
v1.0.0
- Initial release
- Add high-probability number adjacency avoidance logic