Does the 0.5% RTP variation rule apply to all game modes?

Yes. The 0.5% RTP variation rule applies to every mode in your game, regardless of the mechanic.

The rule

All game modes must fall within a 0.5% RTP variation of the base game. For example, if your base game has an RTP of 97.0%, every other mode must be between 96.5% and 97.5%.

The type of mechanic does not matter - if it is declared as a separate mode, the rule applies.

Example

A game with the following setup would not pass validation:

Both the side bet (4.0% difference) and the bonus buy (1.5% difference) exceed the allowed 0.5% threshold relative to the base game.

What to do

If any of your modes have an RTP that deviates more than 0.5% from the base game, adjust their math to bring them within range before submitting.