Knives have always bothered me in role playing games. I always think they don't do enough damage, or don't do enough...something. You watch a knife fight in a movie, or real life, and you will see really quickly just how messy and brutal they can get. Hell, you can see it for yourself if you and a friend have some clothes you don't mind getting covered with sharpie ink; just put on some light grey (white works best really) clothes and latex gloves, each of you gets one of the big black sharpies, and just see how marked up you both get before a line is drawn on what would be a kill. Today, I want to take a look at some of the problems knives face in RPGs and see what, if anything, can be done to bring them back into prevalence.
Everything Is Lethal In The Real World
The first problem we face with knives, and trying to port them over to games, is that in the real world everything is lethal. You can drown an adult in less than 6" of water if you want to. A pillow could fall on your head wrong at night and suffocate you. You could slip on a bar of soap and crack your skull open. Finally, and most importantly, in the hands of a skilled killer - which is what most PCs are - anything can be deadly.
However, having everything be deadly can quickly make a game unfun. I mean, your GM doesn't roll a D1000 to see if today is the day you slip and fall in the shower does she? How about to see if today is the day a car randomly drives up on the sidewalk and nearly hits you? No, I didn't think so. Games have to balance things out, and put the focus on where they want the excitement to come from. As such, everything becomes a whole lot less lethal, at least potentially speaking.
Knife versus a Sword and the sword should win. Reach and power are valuable tools in a fight, and they often make all the difference in the world. However, if the knife were to get inside of its chosen range, it would win. This is why you have such wonderful statistics like "At close range, a knife beats a gun 9 out of 10 times". It's because the knife is made to work at super close ranges.
Again, this is where necessary simplification for games comes in. In actuality, there are at least 3 ranges for melee: Close, Medium, and Long range. A knife is designed to be used as close range. A sword at medium. And weapons with reach, like spears, at long range. Now, there are variances, but that is generally what you have. More variance also comes into play when you consider each style likely has its own close/medium/long range. Hand to hand fighters do; styles with elbows and knee strikes are often designed to be way in close, while styles with longer kicks prefer to have some breathing range. MMA fighters are MMA fighters because they are looking for a personal style that covers all the gaps.
A Maiming Weapon
I know what I said above. I said everything is lethal, and knives can be a very lethal tool. However, a knife's primary function, what it is best at, is more maiming than killing. With a knife, you get cuts in and weaken the opponent and then go in for the kill. You disable the arm, take out the leg, go for the body, and then go for the kill. This is partially why knife fights look so brutal, we see the damage being done - and how rapidly it is happening - and we just wince in pain. Compare that to a sword which is quite capable of killing in a single stroke, and in fact partially designed to do just that.
This brings up more problems in RPGs, because a damage system that keeps track of maiming wounds is by necessity complex. A lot of systems don't even do wound penalties, and of those that do, few apply them to a person's defense. Which means it never gets easier to hit with the knife and land that killing shot. It also means that those earlier shots with the knife do very little to actually disable the person you are fighting.
Honestly, there is a lot that a knife can do that just comes down on being too complicated for most systems. yes, a system could be made to take advantage of the various things a knife can do, but unless you are going to try to code your game to allow for all the stuff reality does, the same effort put into a sword or gun will pretty much always get you further. At least, assuming you care about real world applications.
There are systems out there that do knives better than others. One is the Silhouette Core system. Knives in the silhouette core system are less damaging than a sword, but wound penalties are present - and vicious -, apply to defense, and the damage system is rated for skill to be a big part of damage. In Silhouette Core, a weapon has a damage multiplier, and that is multiplied by how many degrees of success you had to get the damage done. So a knife in the hands of an expert knife fighter, who can regularly hit with more degrees of success, will always do more damage.
I'd also be willing to bet that GURPS does knives well, but GURPS's claim to fame is trying to do everything right, and thus ending up with a very complex system.
Aside from that, the GM can do a lot to help out in these types of situation. There are times when using the dice can just be wrong. A slit throat in someone's sleep is a slit throat in there sleep. Other things like that, or bringing up narrative into play can help make things seem more dangerous, when in actuality they aren't.
Maybe you've got other ways to increase the viability of generally considered 'less lethal' weapons for your games? Would love to hear them.