Tax on gambling winnings: separate flat-rate charge on winnings plus ordinary tax on remaining income. Insertion of section 115BB establishes a distinct tax framework for income by way of winnings from lotteries, crossword puzzles, races including horse races, card games, other games, and gambling or betting by prescribing an aggregate liability composed of a separate tax on such winnings at a specified flat rate and the tax that would be chargeable on the taxpayer's remaining income after excluding those winnings; 'horse race' is defined by reference to section 74A.