The equations are predictions of how an object should behave. Other equations are simple definitions. Of course, there are some exceptions that are used for dramatic effects, but in general we expect to see things behave as they should. Gravity All falling objects respond to the force of gravity according to the laws of physics. Falling objects accelerate according to certain equations.
All objects fall at the same rate, unless they are affected by air resistance.
Likewise, if a game character jumps in the air, that character must come back down to earth according to the rules of gravity. If a game showed objects falling differently than what you normally see, it would not look realistic. Some things bounce better than others, depending on how elastic they are. When you drop a metal ball on the sidewalk, it will not bounce as high as the more elastic rubber ball. Computer game developers must adjust the amount of elasticity of objects, so they will look realistic when they bounce or collide.