Book of 99 — slot review

Book of 99 made headlines across the market with a single number — a 99% RTP, an almost unheard-of return for a video slot. Structurally it's a classic "book": a 5x3 grid, ten lines, a book scatter and free spins with an expanding special symbol in the Book of Ra mould. But Relax added a twist: collect 99 of the hero's symbols and you're granted a bonus retrigger with a guaranteed premium expanding symbol. Thanks to that razor-thin house edge, the slot is adored by strategic players and bonus-clearing grinders wherever the terms allow it. For anyone who prizes the maths over the graphics, this is essential viewing.