Merriam-Webster Collegiate Dictionary - stratagem

 noun  Etymology: Italian ~ma, from Latin strategema, from Greek strategema, from strategein to be a general, maneuver, from strategos general, from stratos camp, army (akin to Latin stratus, past participle, spread out) + agein to lead — more at stratum, agent  Date: 15th century  1.  a. an artifice or trick in war for deceiving and outwitting the enemy  b. a cleverly contrived trick or scheme for gaining an end  2. skill in ruses or trickery  Synonyms: see trick