In this article, I will introduce how to calculate the RTP of slots with free game feature and there could be more than one scatter symbols landing on the reels at the same time

The basic steps are similar, we can calculate the RTPs of standard symbols in base game and free game

Considering there could be more than one scatter symbol on one reel, the amounts of scatter symbols on each reel should be considered. In this case, we need to use array formula to get the event amounts of different scatter symbol amounts

Press Ctrl+Shift+Enter to activate array formula

Then, we can get the expected free game times in base game and free game

Finally, we can get the RTP of this slot

After building the model, we can start adjusting symbols on reels to get a more proper RTP