GAME SYSTEMS
The systems under the nest.
How Steal An Egg actually works: mutation rolls, the fusion machine, treadmill upgrades, and the speed math behind every raid.
Mechanics
Understand
the roll.
Mutations, sizes, fusion and treadmill speed are the four systems that turn a clicking game into a plan.
These pages explain the machinery: how the mutation roll multiplies income, what the fusion machine takes and gives, which treadmill upgrades are worth the grind, and how speed thresholds decide whether a raid succeeds. Where the community disagrees on numbers, we show both figures and the date they were measured.
- Mutations: the roll that makes or breaks a hatch.
- Fusion machine rules and the sacrifices worth feeding it.
- Treadmill economics — upgrade order that pays for itself.
Mutations
Reference all Steal An Egg mutations, including Silver, Golden, Rainbow, Bloom, and Spirit Bloom multipliers. Learn how mutations stack with size, unlock the Sakura In...
02MECHANICSFusion
Learn how to use the Fuse Machine in Steal an Egg. This guide covers fusion requirements, step-by-step instructions, mutation chances, and when fusing actually improve...
03MECHANICSTreadmill Guide
Complete guide to the Steal an Egg Treadmill. Upgrade costs, Speed output, Treadmill vs Pen priority, and the fastest progression sequence for 2026.
04MECHANICSSpeed Guide
Learn how speed gates biome progression in Steal an Egg, optimize treadmill training, manage egg weight penalties, and time your upgrades for consistent escapes.