mt_rand Generate a better random value intmt_rand intmin intmax Many random number generators of older libcs have dubious or unknown characteristics and are slow. By default, PHP uses the libc random number generator with the rand function. The mt_rand function is a drop-in replacement for this. It uses a random number generator with known characteristics using the Mersenne Twister, which will produce random numbers four times faster than what the average libc rand() provides. If called without the optional min, max arguments mt_rand returns a pseudo-random value between 0 and RAND_MAX. If you want a random number between 5 and 15 (inclusive), for example, use mt_rand (5, 15). ]]> The above example will output something similar to: ¬e.randomseed; In versions before 3.0.7 the meaning of max was range. To get the same results in these versions the short example should be mt_rand (5, 11) to get a random number between 5 and 15. See also: mt_srand, mt_getrandmax, and rand.