A "feature buy" is when a feature is available in an online slot. It allows the player to activate a specific bonus feature in the slot instantly instead of waiting for the feature to appear naturally in the course of play. This can give players more control and flexibility in shaping their gaming experience, but it usually costs more than during regular play. It is important to note that this feature is certainly not found in a majority of slots and it does not at all affect the RTP or the probability of winning for certain features.