[RPG] How to help the GM with this problem player?

To me it sounds like your player is a mix of being impulsive and a newbie to roleplaying. The newbie elements (needing stuff explicitly explained and such) should work themselves out with time. The impulsiveness usually needs a little bit of work.

Here's what I did once to rebuff the impulsive players in my campaign:

1. Set up a wonderful campaign arc that involves the "imminent" death of the party.
2. Put impulsive character in a situation where he finds the important "cure"/MacGuffin.
3. Both the MacGuffin and dilemma turn out to be fake.

I did this to deal with a combat monster who kept doing stupid things (shooting up places, making a "peace gesture" that got the party shot at, and spooking an extraction target [leading to his death]), and it worked pretty well- he was the face of the group, and decided that when the "nanite antidote" that was supposed to cure the party's impending doom nanite fun death he would drink the whole thing to ensure he didn't die (because only two party members were actually really in danger of death, him being one). Turns out that there were no nanites, and the antidote was cyanide.

That was the opposite of what I should have done.

Mind you, it didn't destroy my group, the player stopped being impulsive, and life went on (for all but that one guy's character). But it was a stupid, brash, inexperienced GM maneuver, and it could've cost me a player. It did have the upside of making everyone else more paranoid, but the impulsive people are still impulsive, they just put a layer of paranoia on their actions (which I guess makes them less impulsive by definition, but doesn't promote good decision making).

Ultimately, you will run into these brash and (frankly) obnoxious players. It's not even a personal fault in them; the three or so I have/had (as their various states of rehabilitation qualify them) in my group are all really nice guys, but they just don't create a coherent character. So here's what I've started to do with them:

• Common Sense; Shadowrunners will recognize this as a name of an edge, and it basically reads like this: "Are you sure?". I encourage my players to all take this edge for all but the most oddball of characters (usually not an issue, since they tend to be played by the players who can handle themselves well).
• "The Talk"; tell them it has to stop, plainly and explicitly. I actually had to do this with one of my players (the cyanide one, in case anyone was wondering) when they played a crazy sociopath Malkavian in Vampire: The Masquerade. Go to the player and tell them in explicit language that their characters' actions have to stop. No qualifications, no debate. If not, character goes bye-bye entirely, due to the fact that he [insert appropriate gaffe here] (the Malkavian was on the intersection of "Shot up the First National Bank at dawn while wearing a Speedo" and "Built a functional nuclear bomb, fumbled while stashing it away", with the former being slightly more likely).
• Veto; most games include very prominent "ask your GM" clauses during character creation. Call that in. The player will fuss about it. They may leave. If they are that disruptive to the game and the group, however, it may be a necessary evil to tell them that their character cannot a) remain under their control and b) remain in the campaign. It doesn't necessarily mean that the character vanishes from the universe and never existed, but he's a NPC now, retires suddenly, or goes out in a blaze of glory. He does not, however, continue acting as he has and sticking with the group.

Disclaimer: You may have other factors leading to this issue.

Wrong Game: The player isn't actually interested in playing this game; even if they're interested in the setting and mechanics, they don't want to abide by them. This is what I call the "Sparkle Vampire" syndrome I occasionally have to deal with from a player who read all the supplements and got a bunch of ideas ("But the book says cyberzombies are only really, really, really hard to create!) that they then assumed would apply to their characters. These are the sort of people who want to play sentient variants of high-level D&D Monster Manual entries, fully sapient human-form mind animals, and the like. If they were playing Eclipse Phase they'd go for the Octomorph and give it a fancy cybernetic suite including jet thrusters.

Bad Player: I hesitate to call someone a "Bad Player", but it's true that some people prefer to play things revolving around them. While this is natural, some people take this to an additional extreme, and must make everything they play revolve around them all the time. Sometimes this leads to "The Talk" (see above), and sometimes this just means they won't have fun in the game and should pursue something else.

GM Ineptitude: Note that I'm not accusing you here, and I'll keep the examples my own. I used to run an Eclipse Phase game, and I made the players into hard hitting immortal cyborg soldiers. It lasted three runs. My players got bored because they had no consequences for failure. I ran a Remnants game. It failed because the players kept running into issues where their (overly large) group kept falling apart on matters of dogma or running into massively high power gradients. This same group has been in a Shadowrun campaign that lasted for almost a third of a year with weekly sessions, and the reason it ended was due to scheduling conflicts and getting far outside the realm of mortal power. It's not that this even means I'm a bad GM, it just meant that I was aiming for something and my players weren't, and there was a communication breakdown or I tried to push it on them too hard (or I over-hyped them).

To make your question short, and to see if I understood it correctly, we're talking about a player who made his character a certain one and roleplays it entirely different. You added that you think that it comes from inexperience, and that he created this character after you said "no" to some "freak-character"-ideas. You want to help him roleplay the character he created.

As I see it, this problem is made from two smaller ones. The first is that he doesn't see his character as interesting because the character "is normal and normal is boring". The second is that you wanna help him understand why the way he plays the character does not fit the story-world of your game.

Helping him understand that "normal is not boring

This is the more important problem, as it stands in the basis of the entire problem. If he'll see that normal characters can be interesting his "anti-persona" will perish and he'll roleplay a normal character and not a freak one. The main trick here is to show him that normal characters are not entirely normal, i.e. "no person is like the others". In order for that to work, we need to give the character depth.

The easiest way to give depth to a character is through internal conflicts. Having goals and all is nice, but without something that blocks oneself from achieving them it is far less interesting. First thing to do is to go over his character's background and see if he implemented there an internal conflict for his character. If so, show it to him and talk with him about it. If no, sit with him and help him to come with one. The internal conflict doesn't have to be extravagant, but it needs to be there. An example one might be that he loves Vincent's sister but secretly hates Vincent himself, or another like Loves the sister but thinks that he's not good enough for there. I'll take the second one as an example for this section.

The conflict gives us a few things, a few added benefits. It gives the character 2 conflicting goals: "Get the sister and prove that I'm worthy". Now, with those two we also get a kind of an achieving-plan: "If I'll show her that I'm worthy, by getting something amazing done, she'll want me and I'll be able to get her". More than that, the character gets the knowledge that each advancement in order to achieve one goal will drive the other one to the far end.

But the first conflict is even more interesting. The character here has the knowledge that he needs the brother in order to save his lover, but he just can't stand being near the brother. He'll drive the mission onward for two reasons but he'll have doubts about his lover- if he'll marry her he'll be stuck with this brother of hers.

To make long story short, simple conflicts can show the player that even normal characters are interesting and unique. When combined with goals they force the character to take certain steps along the roads, to commit certain actions along the way, that he won't want to do but will make him doubt himself and question himself and see that his problem are far more interesting than those of every freak that he'll encounter.

Another nice way to help him see the importance of conflict is through showing him and analyzing with him certain protagonists that are normal people, from the stories and movies and series (of any form)that he likes. He'll see quite quickly that the conflicts make them interesting.

But he may say that it is not enough. For that there are a few more literary tools that might help him see why normal people are interesting. The first one is having flaws (internal or external) and the second one is using "The Ghost".

Flawed characters are characters that just like normal people aren't perfect. Those flaws can be internal (self-doubts, for example, or a mild paranoia) or they can be external (they're look frightens ordinary people, for once, or a missing hand for the other). The idea is that the character has to deal with the flaw, and one day to find the strength to overcome it. The fight for the overcoming act makes the character far more interesting. A nice example of that can be seen in The Rain Man, where he learns at the end that he can count on strangers/"dumb" persons like he's brother. Another nice example can be seen in the story of The Ugly Duckling who although looking terrible learned to acknowledge himself and to accept the way he looks, to accept his difference.

"The Ghost" is an event from the past that just like a ghost haunts the character to this day. Again, trying to cope with it is what builds a deep character. One example for this can be seen in the movie Inception, where we literally have a ghost- Cob's wife. Another example for this can be seen in the movie Casablanca, where he has to deal with his broken relationship with Ilsa. This Ghost is far more interesting as the originator of the Ghost actually comes back to his life. In Frozen we see another kind of a Ghost- the act that one feels guilty about. Elsa actually killed her sister.

All of these techniques are there for one reason- to make regular people interesting, to give depth to the characters, to make them human beings with goals and drives and psychology.

Helping him see that his character doesn't fit the world

After he understands that he doesn't have to be a freak in order to be interesting, he will be far more understandable about playing a character that fits the world. Then, try to explain to him as calmly as you can what it is in the way he played his character that doesn’t fit the world.

Explain to him that the characters are in a world where being a freak is bad, where achieving one's goals is the ideal. Each and every one for himself, as the saying goes. Give him examples from the way he played his character and analyze with him, in a one-on-one conversation where his way of acting came from. Use the background he created to illustrate to him where your problem comes from.

Then ask him what problems he has with his character, and together try to find a solution. Maybe let him be just a little bit freakish. Maybe he needs to just create a different character. This is basically between you and him. After that show the updated character to the group and get their approval.

When combining those two, you'll get a player who his far more willing to both play the character while also seeing the problems with the way he played his character before.

Combining the two solutions

When combining the two solutions you get a better player, who understands for the future also how to create regular characters that are not freaks yet far more interesting than those freaks will ever be able to be. Furthermore, you get a player who is willing to play his character as written while still making the character fit into the world. Hope any of these helped you.