Como lidar com jogadores que quebram o clima do jogo, exagerando seus personagens

If your players are playing their characters then you are a really lucky GM, and you should be proud of them.

But yeah, I understand. We've spent ages preparing an encounter for the group. We've gone over all their possible approaches dozens of times and put stuff to gently railroad them into the right places to cover every eventuality. And yet still, the group will never, ever stick to our mental script of the encounter.

The Malkavian, completely in character, throws a cake at our Seriously Badass Evil Villain. That wasn't in our mental script! Aaagh! Tell him off!

No. The player has just thrown us a bone, the ability to build on the actions of the character while at the same time showing the personality of our villain. We're a lucky GM indeed.

How does our villain react?

• Does he unflinchingly ignore the missile as beneath him, and let it bounce off and roll away unheeded, perhaps casually dabbing at the cream with a lace kerchief as he berates the party?
• Does the cake just dissipate into nothingness as it flies towards him?
• Does he block it effortlessly with his staff?
• Does one of his minions catch it from the air, crush it, and fling it contemptuously to one side?

O desprezo the villain shows, the way the humor of the situation falls completely flat and unnoticed by him, will only build the villain's stature in the eyes of a player.

(If you conhecer that you have a habitually-cake-throwing character, then you can prepare for it in advance! Instead of "that wasn't in my mental script!" you have the advantage, and can have a response lined up ready! I'd discourage too many OP disintegrations, though: most lower-levels would just wipe it off and say something like "Freaking Malks!". Only a fellow Malk would be amused or distracted by it... and THAT encounter would be a delight to play! "Oh my! Beetroot? Delicious! You MUST give me the recipe! Torturers! Take this one to the dungeon kitchens: I will have his secret!")

As GMs, it's not about us: it's about the players' characters, and about the players' fun. If they're having fun, great. If we're upset because our carefully-crafted atmosphere got ruined, then that's sad... but also just plain wrong-headed.

If we let the players have those characters, and then we place them in a setting in which they cannot both play those characters, and still have fun... then we messed up somewhere. Where?

1. We let some players into our group who are just so mean and ill-spirited that they are out to ruin the game for everyone. Solution: let them back out again.
2. We're just not doing our atmosphere-building well enough, so our sense of atmosphere is destroyed by nothing more than a flung cupcake. Solution: Ask whether our vilão would let his thunder be stolen by a Malk cupcake? Yes? Then that's fine. No? Then get in his head and role-play ele!
3. We are caring too much about setting and atmosphere. We want, perhaps, the players to be hanging on our every word, instead of having fun. Solution: accept that if the players are having fun, we're already winning at being a GM! Even if they aren't enjoying themselves as we had planned!
4. We let the players have the wrong characters for our campaign. Solution: apologize to them, explain what the campaign's about, and ask them to re-roll.
5. We have created the wrong setting for this encounter, given the party and the players. Solution: play it through, learn from it, and change the setting for future encounters to work better with the party dynamic.

You've only talked about retaliatory responses to players who step out of line. Have you tried a group conversation antes the game, so everyone can set parameters and know what they are? That works a lot better than punishing them for crossing lines they didn't know existed.

This is especially important with horror games. Suspense, dread, terror, and the other emotions which horror games thrive on, are delicate to construct and easy to tear down. ALL games require everyone to collaborate if they're going to work, but horror games are less robust in their ability to absorb social contract miscues.

Pre-game flight check: Make sure everyone's playing the same game before you start.

Before a group starts playing a horror campaign, they need to sit down and talk about what it significa to be playing that sort of game. Some horror RPG systems, like Call of Cthulhu, have sections about the implications and necessities of horror gaming. There are also essays on the subject que você pode achar útil.

Some of your problems may stem from a disconnect in the tipo of horror your group is interested in. A gore-heavy story will reward study of the monsters' statistics because it's dismemberment which brings the chills; a dread-heavy story can be utterly ruined by familiarity with the beasts stalking in the shadows. If some participants expect one style and some expect another, the tone will be pulled in multiple directions at once and probably won't survive.

It's important (for reasons I'll get into a little bit later) that this pre-game meeting doesn't just consist of the GM telling the players how it'll be. Good horror stems from things the participants find unsettling, and also requires all the participants to buy into the kind of horror they're agreeing to experience. This means the group should work together to agree on what the game will be like, so it's good for everyone. Your goal should be that everyone at the table, GM and player alike, becomes a co-conspirator working to make the game great for all involved.

Use the right tools: System choice can help or hinder your gamegoals.

Once your group's goals are agreed upon and coherently expressed, you may want to experiment with various systems to find ones which encourage those goals. For example:

A d20 System campaign (which gives hit point and defensive statistics to all creatures) comes pre-packaged with the idea that defeating an enemy is always possível given the right circumstances. That's going to actively oppose any attempt to cultivate "cosmic despair."

Cthulhu Dark, on the other hand, says that if you attempt to fight any monster, you automatically die. This totally re-frames the Investigator's position in the world, and reinforces the implacable nature of the horrors the Investigator faces. (Naturally, Cthulhu Dark is an awful game for zombies-and-shotguns gorefests.)

Make parties that work together.

When players create characters together, they act as a force multiplier to push things in the direction the group wants to go, while also reining in ideas that are counter to the group's needs.

You'll find a number of questions on the site already dealing with the details of party cohesion, including Que tipo de regras promovem uma boa coesão da equipe?. It's a great way to help avoid issues like "My character isn't interested in that," "My character fixes the problem before anyone else can help," and "My character has a worldview totally at odds with the sort of story we're telling."

Some systems have this concept built into their mechanics already, but you can add it to most systems with trivial effort.

Don't force horror on the unwilling.

Most important of all: you have to be sure everyone quer to play the game. If some people are uncomfortable with the subject material, or just bored, they shouldn't feel pressured into doing it anyway. That's the fastest way to get players who disrupt the proceedings. They don't usually do it on purpose, but they will fight the tone of the game every step of the way. If you have players who don't want to play horror, or just don't want to play one particular flavour of horror, don't push them into it.

Take breaks from being scared, and guide action toward productive channels.

Don't go overboard on enforcing the horror experience all the time. A little levity is important, as it gives us a chance to breathe and recover so we can be scared again. Without breaks in the terror, we get overwhelmed and stop being scared. System mastery is laudable, as I'm sure you don't want players who are unfamiliar with the game they're playing. Studying the books means they're interested in what's going on. If you punish these behaviours todos the time, they'll never find appropriate outlets which enhance the game experience.

For horror to be effective, the situation has to actually be (or at least appear) dangerous. If the player feels he can openly mock the Big Bad with no consequences... give him Consequences.

Hurt the character. Not just hit points, but something lasting.

Now, I wouldn't do that at the drop of a hat, and not per se at the "first offense"; but if a player is consistently doing this kind of thing, you have to find some way to re-establish that the Monster is actually dangerous. And yes, sometimes a character dies.

Maybe the monster kills an important NPC in response -- there are lots of options.) But as somebody suggested, if your villain is foiled by a tossed pastry, what kind of villain is he? Throw a cake at Cthulhu. Go ahead, I'll wait... but I'll get in my car and drive 100 miles and wait there.

In the end, if a player realizes he can throw cakes with impunity -- and he's right -- he's just going to keep throwing cakes. Either let the big bad get angry at the disrespect and retaliate (which I think is the lesser option as it actually makes the monster seem weaker); or have him dismiss it -- and the character -- without a second thought. For the villain, the act was so beneath contempt it doesn't warrant a response. Obviously these "heroes" aren't much of a threat.... (ahem)

EDIT: Note: even in the best horror there can be moments of levity. There deveria be moments of downtime where the characters can catch a breath. But in the end, horror is horror.