For any gambling that isn’t keno, bingo, poker or slot machine gaming, you are required to report winnings of over $600, which will be subject to the tax rate. Slot machines and bingo games require you to report winnings of $1,200 or more. Keno winnings of $1,500 or more should be reported, while poker tournament winnings of $5,000 or more should be reported. While gambling at offshore platforms isn’t specifically legal, winnings still need to be reported to the IRS.