Under the Hood
But, as the saying goes, with great power comes great responsibility—having all of the narrative power in his hands puts a lot of responsibility on the GM's shoulders.
Often it fits the players' agenda. They have come to participate in a story, under certain terms, not change it. But this isn't always the case.
Sometimes in an otherwise "regular" game a player may think that he's got something to contribute—the story may flow in a direction of special interest to him, events may unfold in a certain manner that he thinks is better fitting to the game or he may feel that it's especially important for his character to succeed at something.
Other times, the participants—both the GM and the players—wish to play with a different distribution of narrative control, perhaps to a level that the narrative control is distributed almost evenly among the participants.
Here we'll discuss some mechanical methods to handle the situation. However, we'll be discussing these mechanics only from a point of view that there are a GM and players. Games with no GM (or rotating GM, or other variations where there isn't a constant and clear distinction between GM and players) aren't discussed (not to say they're bad, but we can't talk about everything in a single article).
One should note that most of these mechanics work completely on the meta-game level—there's usually no in-game explanation as to why the mechanics exist. As such, they can stand in the way of immersion and the suspense of disbelief for some people.
If such considerations are of much importance to the game you're designing, you may wish to consider sticking to the more standard approach, or seeking other, not mechanical solutions to the problem, which we won't be discussing here.
Creating an Atmosphere
This mechanic isn't so much about narrative control, as much as it is about actively encouraging players to narrate their actions—describe them, basically. If a player describes what he's doing in a manner appropriate to the genre and the desired atmosphere, he gets a mechanical bonus and an increased chance of success.The most common example are the stunts in Exalted: if a player describes his action in a "cool" fashion—that is, fitting with Exalted's jumpy and over-the-top atmosphere—then he gets slight bonuses to his action. Wushu takes the whole thing a step further—the "coolness" of the descriptions determines your chances of success more than the character's actual mechanical abilities.
Such a mechanic has two uses. The first is to encourage players to actively participate, thus creating a better atmosphere and relieving the GM of a small burden of description, which is usually much more fun for everyone involved.
The second use is helping to enforce the genre's rules, especially when they aren't "logical". When you're playing a game in the world of kung-fu movies, jumping from wall to wall and kicking in flight has very good chances of success. In a game of pirates and swashbuckling, jumping from rope to rope and climbing up masts while fighting will likely help you win a fight, instead of getting you killed, which would've been the likely result in the real world.
The main drawback of this mechanic is that it stands somewhat in the way of a more tactical approach to the game. If tactical combat is an important part of the game, having bonuses which are given basically on a whim may be inappropriate.
Signaling the GM
This mechanic allows the players to signal the GM via mechanical means what they'd like to see in the game and what they wouldn't like to see in the game. It doesn't strictly necessitate the GM to act one way or the other, but de facto, going against the players' desires would be the wrong thing to do, mechanically, and thus such a mechanic allows the player to somewhat control where the game goes via their mechanical decisions.There are various examples of how such a mechanic is implemented. In Dogs in the Vineyard, players have the ability to invest in things that they want their character to be attached to, and thus signal the GM that they want the game to focus on these things. More specifically, characters are assigned scores not only to their abilities, but also to their equipment and NPCs which are connected to them. If a player assigns a high score to a certain NPC, it doesn't necessarily mean that the NPC can help the character all that much within the game world—what it means is that the player finds this NPC exciting and wants him to see play, and wants scenes involving that NPC to be more exciting and eventful for his character.
FATE provides a similar system, where a character can be assigned an Aspect (a mechanical feature that gives the character certain bonuses and penalties in circumstances related to it, and may also dictate the character's behaviour) that is connected to an NPC or some organization. For instance, if I'm playing John Smith and I give him the Aspect "my wife means the world to me," then this Aspect will give John a bonus when he tries to save his wife from danger, will give him a penalty when he tries to do something against her desires and may force him to act against his own best judgment when she's in danger. When I give John such an Aspect, I essentially tell the GM, "I want John's wife to be prominent in the game."
Character Control
Now we'll discuss a mechanic which allows the players to temporarily take more control over their characters. Mostly this is implemented via a resource, by the use of which the player can take away narrative control from the GM when it comes to his character. There are many names to this system: In 7th Sea it's called Drama Points. in True20 it's called Conviction Points, in Star Wars systems it's usually called Force Points, etc. (Fate Points in Fate are similar, but can also be used for limited world control, as described further on.)What we're talking about here is a limited resource, which allows the player to say, "just a moment, it's now important for me that something happened to my character."
There are various implementations. In True20 a player can re-roll with a minimal result of 11 (on a d20). In World of Darkness one can buy automatic successes. In the 1st edition of Exalted most of the charms (special abilities) that gave the characters narrative control required the expenditure of willpower. (In this regard we'd like to specifically mention the Perfect Defences from Exalted. These provide the player with narrative control because they allow the player to say, "no, he doesn't hit me," no matter what the GM thinks on the matter.)
On the whole, such a mechanic gives the players the ability to say, "no, he doesn't escape this time," "it's now really important for me to break this door," or "it's really important for me to keep this thought secret."
Such an implementation is very common mostly because it doesn't need to change much in the game's existing mechanic. Most games use a random element when determining the result of actions, and thus it's easy to allow players to reduce the randomness in their favour.
A different implementation, somewhat less common, was discussed in the previous article, "I Fell and I Can't Get Up": when there's a mechanism of positive feedback (a "death spiral"), then using the appropriate resource a player may restart that mechanism and remove its penalties. In True20, for instance, this allows a character to get out of a state of shock. In other implementations it may allow characters to ignore the effects of wounds, fatigue, or even come back from death's doorstep.
Using this mechanic in a game requires you to consider the nature of the characters. Namely, you must consider the following point: are the characters heroes because they do heroic deeds, or do they do heroic deeds because they are the heroes? If the characters are just normal people, and they become heroes because of their courage, their desire to help and sheer luck, then this mechanic doesn't fit in. Such a game tries to be "realistic," and in the real world, heroes are called heroes only in retrospect. However, if the characters are unique merely because they're the central characters of the story, people who are better and more able than normal people, people to whom the laws of the world don't always apply—then such a mechanic will certainly help, and will help establish the characters' role as heroes.
Of course, it is possible to adjust to what extent the characters are "better" than regular people. There's a big difference between getting an extra 5% chance of success and getting an automatic success. Another way to adjust this is to control the availability of the resource. (You can read more on resources in the first article, "When the Juice Runs Out".)
World Control
Last but not least is a mechanic that gives players the ability to take narrative control over the whole world—simply take control into their own hands.This can be done on several levels.
One option is to allow players to narrate a certain scene but with known limitations. This gives players the ability to contribute more directly and inject their own vision of the world into the game, and it also makes the GM's job easier—but this usually comes with limitations that mean the player can't really affect all that much. (And the GM is still above the player and has veto.) An example of this mechanic can be found in Don't Rest Your Head (as an optional mechanic), where in each conflict, the one who narrates it is the one who won it. So, it's still only a single conflict, and the results are more or less predictable once you know who prevailed, but it still gives the players some narrative power and can provide for a nice change of pace.
Another option is essentially to increase the power of the resource described in the previous section. Thus, using "Drama Points," one is able to not only affect one's own character, but also state facts about the world as a whole and the NPCs in it. This is the case in FATE, for instance. This gives characters control over the world and takes it from the GM, but this control is limited by the resource. Usually, most of the narrative control is still in the hands of the GM, but players will occasionally add a fact here and there. This is a good idea if you want the players to share the experience of narrating the game and allow them to add elements of their own into the world, but still wish to keep the whole thing reigned in and relatively "classical".
A more extreme version is one where players get a lot of narrative control—they can state facts and add elements into the world on a regular basis, sometimes on par with the GM himself.
Such a system can be seen in full force in Houses of the Blooded, for instance, where the players get the ability to dictate something about the world and the narrative with every action their characters undertake. Every test consists of the player rolling a number of d6 dice and summing them up, with the aim of getting 10. If he succeeds, he gets a privilege—he can dictate whether the action succeeded or failed (the choice is up to him). If he fails, the GM dictates it. On top of that, the player is allowed to set aside some of the dice as a bet and not use them in the roll. If he still manages to get 10, each such die allows him to add a detail to the results of the action. For instance, my character is trying to jump from one roof to the next chasing a rogue. I put three dice aside and manage to get 10 with the remaining dice. Did I manage the jump? No (it's up to me to decide, I have 10), but I land on a balcony (first die), and a young maiden is standing there beside me (second die) and she offers me safe passage (third die). Moreover, the situation is similar when a character is trying to find something out about an NPC or the world: Do I know anything about this man? Yes (10), he's a renowned swordsman (first die) and he's also the duchess' lover (second die).
In addition, Houses of the Blooded provides the players with a resource called Style Points, which function in a similar manner to Fate Points in FATE. They allow the players to gain more dice on a roll, and they also allow them to change something about the scene—add a detail that wasn't there. Perhaps the ground is snowy and slippery? Perhaps there are red curtains on the wall? Or maybe the window on the second floor is open?
What this system does is take much of the burden of creating the story and the world from the hands of the GM and put it into the hands of the players. They can tell the GM directly and without "asking for favours" what they want from the game, what interests them and how they want the story to continue—it's up to them. "Wouldn't it be cool if he were part of a secret society?"—he is now. "Is this the hospital where I've worked?"—I don't know, you tell me, what do you find more interesting? "How did he lose his hand?"—what do you think?
But this mechanic's great power may also be its problem. On the one hand, the GM must understand that it isn't "his game" anymore. It isn't always his story, those aren't always his NPCs. Everyone can say something new about the characters, the world and the story. The GM must accept that the characters might be on their way to explore ancient cursed catacombs underneath the city, full of lizardmen and forgotten textsÖ which up to a minute ago, he didn't know existed. On the other hand, the players must realise that the game is now much more "theirs" than it usually is—they have responsibility close to the GM's when it comes to developing the world and the narrative. They need to be active, and they can't be smartasses—such power in the hands of a player who isn't serious about the game can quickly bring the story or the world to ridiculous places.
Such a mechanic is in place when the characters have great impact on the world, when the feeling of power that the players get is adequate to the power of their characters. One must also note that this mechanic, when used so extensively, may reduce the focus on the individual characters and shift it onto the narrative as a whole.
Summary
So, who's the GM here? Who says what happens, when and how? It depends on the mechanic you choose—although the GM remains GM, in that he is still responsible for the narrative and the world more than anyone else, even if he doesn't necessary control them more than anyone else.For keeping genre conventions, the first mechanic ("Creating an Atmosphere") is useful—by making certain things easier, you will give players an incentive to do these things and let the GM understand that such actions are supposed to happen.
If you want heroic characters that aren't given to the whims of fate and have some control over the future expecting them, you may use the second mechanic ("Signaling the GM") or the third one ("Character Control").
Lastly, if you want a game where the players actively contribute to the creation of the story and the world, you can consider using the fourth mechanic ("World Control").

