ALTHOUGH FREE REPLAY FEATURES OF PINBALL MACHINES HAVE BEEN RECOGNIZED AS LEGAL BY STATE AND FEDERAL COURTS, BINGO MACHINES' MORE EXTENSIVE RELIANCE ON FREE REPLAYS HAS BEEN DEFINED AS GAMBLING. THERE ARE ABOUT 70 MODELS OF BINGO MACHINES. ALL ARE DESIGNED TO CLOSELY RESEMBLE PINBALL MACHINES SUPERFICIALLY, BUT DO NOT LOOK, FEEL, OR SOUND THE SAME. PART OF THE MACHINE'S GAME IS SIMILAR TO THAT OF REGULAR BINGO. IN ADDITION THE NUMBER OF FREE REPLAYS TO BE WON RANGES FROM 4 TO 600. CERTAIN MODES OF WINNING AND GAME ADVANTAGES INCREASE A PLAYER'S CHANCES OF SUCCESS. THE BINGO MACHINE'S MAIN DISTINGUISHING CHARACTERISTIC IS THAT IT IS A MULTIPLE-COIN MACHINE, ALTHOUGH IT IS POSSIBLE, BUT UNLIKELY, FOR A PLAYER TO PLAY A COMPLETE GAME WITH A SINGLE COIN. THE MACHINE HAS INTERNAL CHANCE SELECTION CIRCUITS, ACTIVATED BY ADDITION OF COINS, WHICH ARE OUTSIDE THE PLAYER'S CONTROL. A BUILT-IN GOVERNOR AUTOMATICALLY ADJUSTS THE CHANCES OF OBTAINING GREATER SCORES, BUT OPERATES ONLY AS COINS ARE ADDED. BINGO MACHINES, IN CONTRAST TO PINBALL MACHINES, ARE RELATIVELY QUIET DURING PLAY. THE FBI LABORATORY CAN ASSIST LOCAL AUTHORITIES IN CONSULTATION, EXAMINING EVIDENCE, AND PROVIDING EXPERT WITNESS TESTIMONY ON BINGO MACHINES. ILLUSTRATIONS, A DETAILED CHART LISTING COMPARATIVE FEATURES OF PINBALL MACHINES AND BINGO MACHINES, AND FOOTNOTES WITH REFERENCES ARE INCLUDED. (CFW)