In video games, when you die you restart from the last save. If it is a nice game, it will auto save, but the annoying ones you have to manually save. Anyways some games, when you reload a previous save, sometimes the environment changes. An example would be one of my favorite games, XCOM Enemy Unknown. It is a great game I highly recommend. The premise of the game is that aliens are invading earth and you are commander of XCOM which is fighting the aliens. Their are two different types of gameplay, the first is base management. This is the part where you study the aliens and improve your armaments. Sometimes randomly generated events occur. Like a terror strike by the aliens. The other gameplay type is a turn based combat. When you reload the base management part, it is different each time. On the other hand when you are combating the aliens, everything is exactly the same. This got me thinking. If you were to reload the world would it be like base management and things be different, or would it be like the turn based combat part and be exactly the same. This may seem like an obvious answer. Of course it would be the same, it wouldn't make sense if it weren't. But here is the problem. In the subatomic level certain events are completely random, their is no cause. Like weather or not a particle will quantum tunnel or not. Would these subatomic particles behave differently when you reloaded the world?
See I can do a serious post.