Terraria Seed Prefix Guide

Ever wondered why there are random numbers in front of the world seed? Well now you don't have to!

What are seeds?

Seeds are a variable string of numbers (and sometimes letters) that determine the output of an algorithm or function. Usually, if no seed is entered (or there isn't an option to use a seed), the algorithm will generate one automatically, so that no two results are the same. In video games, this adds a lot of replay value.

In Terraria, whenever you copy a world's seed, you'll see some numbers at the beginning, separated by periods (.), which correspond to certain values.

What do these numbers mean?

The first three numbers determine the type of world generated, while the latter numbers determine the shape and features of the world.

The first number determines the size of the world. 1 for Small, 2 for Medium, and 3 for Large.

The second number determines the gamemode. 1 for Classic, 2 for Expert, 3 for Master, and 4 for Journey.

The third and final number determines the evil. 1 for Corruption, and 2 for Crimson.

Why should these be important when sharing seeds?

First of all, giving people the latter number and saying "go 6,400 m west" will not be feasible on small worlds, due to being, well, small. If you're wanting to share an evil structure you found, you'll have to specify the evil you found it in as well. For the most part, the gamemode doesn't matter though.

Final Thoughts

Now you know how to tell how to generate a world based on its seed. If you input the seed into a new world with the specified options, it will automatically fill out the options for you, making it less stressful to generate that overpowered seed you were given on Reddit. That's all for this guide.