'it will come back to you'

[Salacious B. Crumb]

Karma is funny because it's really just common sense packaged in a whole shitload of woo.

Of course good things are more likely to come your way if you act good.  That's because people like and appreciate others who are kind, generous, and helpful, and will provide that person with a myriad opportunities to succeed in a myriad of ways in return, often.  "You know who should get the raise?  Johnson.  He's always on time, does good work, and is liked by his peers."  

Conversely, if you act badly, you 'invite' bad things to happen by slowly ostracizing yourself from mainstream society and being forced to interact with other assholes, who may be cheats, or violent, or whatever.

Karma, in terms of thinking things or watching things (like that movie) doesn't exist.  The only energy one's body contains are:

Electricity, generated by...
Chemical reactions, which cause...
Mechanical responses.
And, I guess potential energy.

That's it.

And as others said, the universe really doesn't give a shit if you watch a gory movie, have hot sex, get into a heated argument, help someone, hurt someone, watch Duck Dynasty (although I will ridicule anyone for that ), win the lottery, kill your spouse, rescue an animal, join a cult, etc.....

I agree, karma is just another made up, superstitious way of getting people to act a certain way, or to please a certain twisted mind that something bad will happen to someone, if they harmed you.