We’re writing this e-book to put experts and non-experts on the same page about reinforcement learning (RL).The conversation around RL is polarized: some claim it is the direct path to AGI, others dismiss it as a dead end. Our aim is to replace slogans with evidence. We show where RL genuinely adds leverage for building Al agents and where it does not, so developers and engineers can treat RL as a practical tool rather than a creed.