A screencap from the opening credits of “Black Lagoon”
The term “gratituous violence” is nowadays almost interchangeable with “explicit violence” when talking about media; both are used to describe intensely violent works such as horror films and crime fiction. However, there is a distinction between them that is highly subtle and which quite clearly places them as opposites as critical viewpoints. Gratituous violence is that which is unnecessary in narrative terms – it is there to titillate or elicit a basic response of excitement or revulsion. There is a quite specific sense of intent in the word “gratituous” that implies the content is unneeded.
“Explicit” violence has no such intent or quality distinction; it is simply violence which is graphically depicted.