Collisional kinetic equations constitute an example of entropy-dissipating dynamics for which a large-time behavior results of a delicate balancing of convection (free transport) and reactions (collisions, tumbling effects, degenerate diffusion). The ability of a numerical scheme to capture correctly such a balance is easily checked by means of moments of the kinetic density: positivity, total mass preservation, constant macroscopic fluxes, ... etc. Well-balanced schemes, a term coined in 1996, proceed by handling numerically both convection and collisions as a whole "lumped" discrete operator. Relying on seminal contributions of "spectral methods of kinetic theory" (sometimes called "Caseology"), accurate schemes can be built onto a S-matrix formalism, along with techniques of "matrix balancing" (e.g. Sinkhorn algorithm).