Mini strategy series @soerenbax: The #ThirtySixStratagems, a collection of ancient Chinese military thought and experience.
Characters of the tenth of Thirty-Six Stratagems: 笑里藏刀 (笑裡藏刀) – Xiàolǐcángdāo. 笑, xiào: smile. 里, lǐ: inside, behind. 藏, cáng: hide, conceal. 刀, dāo: knive.
Meaning: Pretend to be friendly and peacefully, but secretly preparing and waiting for an opportunities to strike at the opponent.