Combine island seeds

A single island is just the start. Crucible lets you combine multiple islands into one map, so you can build archipelagos, multi-landmass layouts, connected continents and more complex terrain without sculpting it by hand. Each island carries its own seed and slider settings, so you can mix different terrain styles in one map.

How does combining island seeds work?

• Add islands: click to add another island to your map, or press N. Each island gets its own seed, and you can randomize or paste a saved seed to create its terrain independently.
• Select an island: double-click an island to select it and edit its sliders independently. Click in the water to deselect, or press Escape.
• Customize each island: each island has its own full set of sliders (landmass, mountains, buildable ground, cliffs, etc.), so you can make a rugged mountain island next to a flat prairie island, or mix any terrain styles you want.
• Position and rotate: drag each island to position it on your map, and spin it to rotate the coastline to face any direction.
• Terrain scales automatically: terrain height and noise scale with the island size and your map size, tuned around Rust’s procedural generation so the result feels natural in game. Blending happens automatically where islands touch.

Tips

• Set your map size first: choose your world size before adding islands, then place islands within it. This ensures all terrain scales correctly to your map.
• Mix island sizes and styles: combine a few larger landmasses with smaller ones for natural variety. A big continent with tiny islands nearby feels more organic than uniform-sized landmasses.
• Use saved seeds: select an island (double-click to select), then open the seed gallery and apply a saved seed to that selected island only. This changes only the selected island’s terrain to your favorite seed, leaving all other islands unchanged. Reuse good terrain shapes across multiple map projects this way.
• Save the whole layout: when no specific island is selected, click save to favorite the entire multi-island setup as one seed file. Apply this favorited seed later to recreate the whole group of islands with all their positions, rotations, and slider settings intact. Share the group with other map makers, or reuse the whole layout across different projects.
• Live preview helps: use the 3D and 2D preview to check how islands blend together and how the overall map layout feels before exporting.

A top-down view shows the layout clearly, with each island as its own landmass:

When the layout looks right in the 3D preview, export it and bring it into RustEdit.