[BruceZ]

Computer generated random numbers are called "pseudo-random" numbers for this reason. They are generated by a formula, and they are predictable to someone who knows the formula and the seed, but they are intended to be impossible to predict by someone who does not, and they are intended to exhibit the same statistical properties for a particular application, such as poker, as you would expect from truly random numbers. There is no way to ever completely guarantee this performance, but there are mathematical methods for evaluating it.

Truly random numbers may be generated from physical processes which depend on quantum mechanics such as radioactive decay. Also, thermal white guausian noise may be used, such as the noise you receive when you are between channels on a TV or radio. Some poker sites utilize these methods, and they should be truly random.

On the other hand, hand dealt games are certainly not random, and they may not even be as "random" as pseudo-random number generators.