SAC on a Mujoco Suite

Key Insight

SAC (Soft Actor-Critic) is the modern default for continuous control because it folds an entropy bonus straight into the objective — it follows maximum-entropy RL, maximizing reward and keeping the policy as random as it can afford — so it explores on its own and stays robust without the hand-tuned action noise DDPG and TD3 lean on. Running it across a MuJoCo suite of increasingly hard bodies — HalfCheetah, Walker2d, Ant, and Humanoid — tests whether one algorithm with one hyperparameter setting can scale from a simple runner to a 17-joint humanoid, and SAC's reputation rests on the fact that it usually can.