Under a contingent fee arrangement, the attorney for the plaintiff faces no consequences, other than lost time and effort, for bringing a suit that loses, but he can collect huge fees (typically 30% to 40% of the damages awarded) if he wins.
It should be borne in mind that, in virtually all English civil litigation, damages are merely compensatory.
In the United States the "American rule" is generally followed, each party bearing its own expense of litigation.
However, after the U.S. Supreme Court's decision in Octane Fitness, LLC v. ICON Health & Fitness, Inc. on April 29, 2014, it is now easier for courts to award costs for frivolous patent lawsuits initiated by patent trolls.
A very limited version of the English rule was adopted in Texas during the 2011 legislative session that applies only to the filing of a baseless lawsuit.