I would add that the way the contact constraints are solved decides what kind of artifacts you will be getting and you need to understand that to be able to und

I would add that the way the contact constraints are solved decides what kind of artifacts you will be getting and you need to understand that to be able to understand precision of your simulation. Even for a videogame this would be important. You may want to know if it is possible for fast moving objects to pass each other or not. You might then want to limit the velocity of objects (a cheap trick to solve the issue, but very effective), or you might want to choose an engine specifically for this (for example if you make a billiards game or a shooter).