Raisim can be fully deterministic given the contact solver iteration order. This order can be set by raisim::World::setContactSolverIterationOrder.

Determinism is important because of the two reasons. First, determinism allows you to control stochasticity of simulation yourself. This makes many sampling-based stochastic optimal control methods possible. Second, determinism often means bug-free reliable simulation. Non-deterministic simulation is often caused by unintended memory read/write. It is very unlikely that programmers of a simulator intentionally implemented stochasticity in simulation. There are very few exceptions, such as stochastic contact solvers, but they are very rare.