Writing a general-purpose rigid-body physics engine like PhysX or Havok is probably overkill for most games (unless you’re a big enough company like Blizzard wh

Writing a general-purpose rigid-body physics engine like PhysX or Havok is probably overkill for most games (unless you’re a big enough company like Blizzard who can recruit developers specialized in physics). The Newtonian physics itself isn’t really that hard (unless you’re doing robotics-style articulated bodies), but detecting collisions and resolving contact and friction forces is where most of the difficulty lies in. But a lot of simpler, specialized stuff is perfectly doable even for indie devs. For example, if you’re writing a platformer, chances are that you don’t need to go full-realism and only need “pseudo”-physics with lots of assuptions. Maybe all of your objects only need box or sphere colliders so you can greatly simplify your collision detection. Or maybe you just need physics for some effects (such as ropes or cloth), which you can code easily with minimal research. Remember, when you’re writing games, you don’t need to go full realism, you can probably “fake” a lot of things!