One of the leading pieces of advice for any type of design is KISS. In long, it stands for: Keep It Simple, Stupid! In even longer, it means that you don't want to over complicate your game (or other thing you are designing) because as you build in complexity, you are also building in points of failure, points that may not be able to take the stress as well, and making it harder to understand the overall scheme of how things are supposed to work. As such, many schools of game design (especially those that go with more Narrative Control based focus) have begun to look at finding the simplest yet most flexible mechanic that they can have. Today, I want to talk about some of the strengths, and weaknesses, of those types of mechanics.
Before doing any discussion on the good and bad of these mechanics, we need to find one that is both simple and yet highly flexible to use as an example. For this, and with numerous choices to go with, I'm settling on the core die rolling mechanic used in John Wick's games Houses of the Blooded and Blood and Honor. How this system works is like this: for every action you have a pool of dice, and you roll that dice then tally the sum and try to get above a 10 (these are six sided dice btw, so once you have 4 dice it is fairly easy to beat a 10). If you succeed, you get to narrate the outcome of the event. If you fail, the GM narrates the outcome. Then, a bit of added complication is put in that lets you wager a die from your dice pool for the chance to define more should you win the roll.
This is an insanely simple system that can literally do everything, because you're rolling for narrative control not necessarily success or failure. You could remove everything but this mechanic and have a game. (Think about it, you assign 6 dice to a player. They use a pool of 6 dice for every roll. They choose the action, you choose when it is a roll, at which point they decide if they want almost guaranteed narrative control or the ability to define more. Then go with the game). But, it's not without its problems either.
I want to start with the good, so we're going to start there. On the good side, a simple but flexible mechanic is easy to remember. Especially when you're new to a game. It is a lot easier to remember, "I grab 7 six sided dice, and roll to try and beat a 10;" than it is to remember,"I roll this D20, add my skill ranks, then my trait, then compare it to the difficulty from the gm, and then have to figure out how many multiples of 5 I beat the roll by." This helps speed up the game, and helps bring in new players because the system isn't as much a barrier for them to get in on the action.
Then, there is the flexibility of the system. Since we're rolling for narrative control, there doesn't need to be as much fuss put on other things. Also, a failed roll is not necessarily a success - nor is a successful roll necessarily a success. This means that the story can be more, well, story-like because the success/failure of the task isn't a punishment so much as it is a choice. You didn't lose and end up in captivity, you chose to put your character there. Not only that, but even if the GM made the choice, all it takes is a simple roll to get back out and put the ball back in your hands.
The above two points, as awesome as they are, don't mean that all is gravy. There are a few problems, and some of them aren't even for playing the game. One problem you can come across is that with the power of narrative control being bandied about, some games will go off the tracks a lot faster than they otherwise would. Both early test runs I saw of Houses of the Blooded turned into "who could throw whom under the bus the fastest/worst" fairly quickly, and instead of being dramatic tragedy it was almost a dark comedy. Fine and good for us if we had fun, but not the point of the game.
Then there is the problem that with the system being so simple, things can get glossed over really fast. A common complaint about RPGs is that certain things that are quite involved (say, meeting someone at a bar and getting them to come home with you) are a lot more involved than the simple die roll that most games use. Some even say that the added die rolls, and the added chances of failure or things going wrong, also bring a level of tension to the game. When everything can be done with a single die roll, there is a chance for some people to lose focus or to not see significance of certain things. Yes, a good GM can get around that, but they have to work a bit harder to do it with a simpler system than a more complex one.
Finally, it becomes easier to cry foul with a simpler and more flexible system. Foul may be a number of things from favoritism to just it being unfair that such an important thing hinged on one roll, but it is there to be called. Favoritism is perhaps the worst, especially if it looks to the players that the GM will give success to Lucy, but less likely to do so with Tom, Steve, and Glenda. The reasons could be varied, like small problems coming from Lucy's success, or Lucy being new and trying to let her have fun, but that doesn't mean the other players fun won't be potentially harmed by this.
There are likely other strengths and weaknesses that I've missed here, but these are some of the most prominent that can crop up with a simple design. This doesn't mean that "Simple" should be avoided, mind. Just that you need to know that there are pitfalls as well as boons. Tomorrow (or later in the week) I'm going to take a similar look at more complex mechanics.