Wave

A wave is composed of ten enemy units that are usually dwarfs. The expections are bats, which always arrive on every 4th wave. One wave appears at the left edge of the screen on the path after each player pick.

On each further wave, enemy health and speed increases, with lives cost upon reaching exit increasing after each wave of bats, starting at 1. Enemy armor increases slowly during a game until capping, with exact amount dependent on difficulty. Damage reduction is slightly nonlinear 6%*armor/(1+armor*0,06). From wave 17 onwards enemy units will also have minimum speed below which they cannot be slowed by gems.

Each wave also has a primary weakness to gem type, and there's some evidence of secondary neutral types, such as (dark) emerald on amethyst waves, or (pink) diamond on ruby waves, that is not fully understood. After wave 41 in Survival, all enemy units will have Amethyst weakness, but until then it varies:

List of weakness by level:

  Damage multipliers for damage colour type vs enemy weakness:  