Originally 'to storm and capture' (攻城略地). Borrowed its modern gaming sense from Japanese (攻略 kōryaku = strategy guide), which then spread to travel, beauty, and dating guides.
usage
Common collocations: 旅游攻略 (travel guide), 游戏攻略 (game walkthrough), 做攻略 (put together a guide), 跟攻略走 (follow a guide).