Hindsight Experience Replay (HER) is a reinforcement learning algorithm that allows agents to learn from past experiences, even if the desired outcome was not achieved. This approach enables agents to learn from their mistakes and improve their performance over time. HER has been shown to outperform other reinforcement learning algorithms in various tasks, including robotics and game playing. --- Why it matters: HER matters because it provides a more efficient way for agents to learn from experience, which is crucial in complex environments where trial-and-error is necessary. Source: https://openai.com/index/hindsight-experience-replay