In roulette, the first dozen includes numbers 1 to 12. The probability of hitting a number in this range depends on the total numbers on the wheel: 37 in European roulette (including one zero) and 38 in American roulette (including one zero and one double zero). Consequently, the probability of hitting a number in the first dozen is approximately 32.43% for European roulette and around 31.58% for American roulette, indicating a relatively high chance of winning from this section in both game types.