Slick, Sly an Subtle
"Frank Marshall, the great American Master, staunchly upheld the view that in Chess it is more blessed to give than to receive. He despised players who were always avid for material gain, and his games are studded with speculative sacrifices and gimmicks. Even on the rare occasions when Marshall was defending, he favored indirect defenses which looked like oversights. To Marshall it was second nature to set pitfalls for the materialists by temperament.
Greed has been many a player's undoing. In his concentration on material gain, he often overlloks pitfalls based on a tactical finesse. Relying on the principle that material advantage generally assures victory, he is prone to forget other principles, those that warn against neglecting the King's safety, running into embarrassing pins, losing valuable time, and the like."
Take a look at the following position. Black is a piece ahead, but he has to be very careful on how he plays because the White pieces are very active and exert an uncomfortable pressure. White's a1 Rook is under attack and has to move somewhere. Here White's Rook move, which passes for a would-be defensive move, turns out to be the prelude to a sly swindle.