Roulette, blackjack and table games
Can betting on both red and black guarantee I break even?
Direct answer
No. A zero (and double zero where present) loses both colour bets, so combined wagering still faces the house edge.
How to use this answer
This answer is based on the mathematical principle or published rule identified in the source below. If the question involves a live betting market, confirm its settlement definition before applying it to a specific bet.
Separate the game’s mathematical probabilities from the casino’s house procedure. The odds may be calculable even where split, surrender, side-bet or payout policies differ between tables.