明修栈道，暗渡陈仓
míng​xiū​zhàn​dào, àn​dù Chén​cāng

feign diversion

明修栈道，暗渡陈仓 (明修棧道，暗渡陳倉) míng​xiū​zhàn​dào, àn​dù Chén​cāng
feign diversion
To deceive others by carrying out a visible action to conceal one's true, secret activities or intentions.
military stratagem
A historical tactic involving a public diversion to mask a secret troop movement, specifically referring to Liu Bang's campaign in 206 BC.

Sources
Definitions
CC-CEDICT