  We summarize a series of numerical experiments of collisional dynamics in
dense stellar systems such as globular clusters (GCs) and in weakly collisional
plasmas using a novel simulation technique, the so-called Multi-particle
collision (MPC) method, alternative to Fokker-Planck and Monte Carlo
approaches. MPC is related to particle-mesh approaches for the computation of
self consistent long-range fields, ensuring that simulation time scales with
$N\log N$ in the number of particles, as opposed to $N^2$ for direct $N$-body.
The collisional relaxation effects are modelled by computing particle
interactions based on a collision operator approach that ensures rigorous
conservation of energy and momenta and depends only on particles velocities and
cell-based integrated quantities.
