There is a certain hypnotic quality to violence, I find. Playing a game where it is a central theme runs the risk of being seduced by it, of allowing it to be the one and only raison d'être of the entire experience. A cult of violence exists within us all, and particularly in our roleplaying games. This sounds like an indictment, but it's not. For one thing, as I recently said over at Really Bad Eggs, the depiction of something is not the thing in itself. The depiction of violence is not violence, and treating it as the real thing is ludicrous. The depiction and experience of violence is something central to being human, and with it we can explore other things. Even when it appears senseless, it can really be a commentary on the purposelessness of life, the randomness with which we perish for senseless and incomprehensible reasons, or most simply the cruelty of man.
All of these things are inherent in the depiction of violence. But I find that there are certain settings and games, most particularly Warhammer 40k comes to mind, in which violence serves only as an end in itself. This is probably because 40k came into being as a war game and, like all war games, the story served as a reason to kill. There seems to be something sinister about 40k, though, particularly amongst the most iconic of groups: the Space Marines. They exist solely as arbiters of death and destruction. They are quite literally ubermensch, towering over most human beings, possessed of the strength to rip doors from concrete walls and crush skulls in their hands. They have excessive weaponry: exploding plasma-bolts, chain-saw swords, flamethrowers that can liquify bone.
What's my problem with these Space Marines? I'm not really sure. I like Warhammer 40k (though I think that Warhammer Fantasy has a much more cogent and well thought-out setting) but it seems somehow to be lacking in the content department. It has one or two themes, and it hammers them home with the subtlety of a screaming drunk. It espouses close-mindedness and racism, but in a setting where such things are valuable survival tools. It is, as the kids are saying these days, grimdark.
But it also runs the danger of falling prey to the treacherous siren-song of violence. While it may be dangerous for characters in the Imperium to think too much about their actions, the same is not true of their players. When players stop thinking and simply relish in the gore they are unleashing, is something not gone wrong? Violence without content has no depth beyond the most juvenile possible delight in destruction, and while it can be fun for a little while I cannot see myself engaging in a long-term 40k roleplaying game; at least not Deathwatch, which focuses on the Space Marines.
There are other elements that I enjoy and respect; the insane anarchism of Chaos, the hopeless (and very human) struggle of the Imperial Guard, and the clandestine workings of the Inquisition all have a lot of interest for me. But the superhuman muscle-flexing of the Space Marines seems somehow to be lacking, in many cases. That's not to say I dislike all depictions of the Space Marines, but that the ultraviolent trappings seem to be a pitfall that is hard to avoid. In their best incarnations, Space Marines are battle-brothers, knights of the horrific future age where all things are dark, an elite warrior-brotherhood, monks and templars. At their worst they are savage thugs who murder indiscriminately and casually and, worst of all, without examination by those who play them.