More sophisticated physics models of creature movement and collision interactions require greater level of computing power and a more accurate simulation of solids, liquids, and hydrodynamics.
[3] Some games, such as Boneworks and Half-Life 2, apply forces to individual joints that allow ragdolls to move and behave like humanoids with fully procedural animations.
This allows to, for example, knock an enemy down or grab each individual joint and move it around and the physics-based animation would adapt accordingly, which wouldn't be possible with conventional means.
This creates problems with collisions - sometimes the projectile travels so fast that it simply goes past a thin object without ever detecting that it has collided with it.
However, simply shooting a ray in the direction that the weapon is aiming at is not particularly realistic, which is why modern games often create a physical projectile that can be affected by gravity and other forces.
In FIFA 14, developers were required to fix code related to the drag coefficient which was inaccurate in previous games, leading to a much more realistic simulation of a real ball.