Should I use a random engine seeded from std::random_device or use std::random_device every time

Question

I have a class that contains two sources of randomness.

std::random_device rd;
std::mt19937 random_engine;

I seed the std::mt19937

Answer 1

The standard practice, as far as I am aware, is to seed the random number generator with a number that is not calculated by the computer (but comes from some external, unpredictable source). That should be the case with your rd() function. From then on, you call the pseudo-random number generator(PRNG) for each and every pseudo-random number that you need.

If you are worried about the numbers not being random enough, then you should pick a different PRNG. Entropy is a scarce and precious resource and should be treated as such. Although, you may not be needing that many random numbers right now, you may in the future; or other applications could need them. You want that entropy to be available whenever an application asks for it.

It sounds like, for your application, that the mersenne twister will suit your needs just fine. No one who plays your game will ever feel like the teams that are loaded aren't random.