\(\frac{1}{3}\)
Explanation
To find the probability, divide the number of acceptable outcomes by the total number of possible outcomes. The acceptable outcomes are 1 and 2, so there are 2 of them. The total number of possible outcomes is 6. So the probability of rolling a number less than 3 is \(\frac{2}{6}\) which reduces to \(\frac{1}{3}\).