War violence, sword fighting and gun play. Lots of Blue blood (because of the lack of oxygen and the fact that they're all aliens on Mars, except for John) not much of it is red. The violence does get intense.
The alien dog 'Woola' is kicked and beat by several aliens while he whimpers. This happens until John Carter puts a stop to it.
An alien is branded with a hot piece of iron for making a mistake. She is told if she makes another mistake she'll be executed.
A character jumps into the "white ape" arena and is caught by one of the white apes. It rips her in half. You only see the shadow.
John Carter kills a white ape from the inside. He breaks free by tearing through its back. He is covered in blue blood.
A character gets beheaded and we see his severed head on the ground. Not very graphic though.
A mans arm is cut off and blue blood is seen gushing out of the wound.
Carter confronts an entire tribe of green men and kills the majority of them. The scene is quite graphic although because the blood is blue, it isn't as gory as it sounds.