For gaming purposes, at least three types of stereotypes exist:

Is your game master being a hard core, unforgiving, and generally mean person? Talk to him or her, and explain that the game rules are just guidelines, not strict interpretations of each and every aspect of the game. All good storytellers appreciate being reminded of the fact that they are both in control of the rulings and that they are or are not doing a good job. Most storytellers will take a step back and lighten up on the NPCs and critter fodder they create if you just tell them they’ve gone too far. The abuse of certain mechanics in such a way that it makes playing impossible by a GM that has no remorse may mean that you must take the ultimate step, leave the game. If your group contains friends, make sure to keep your relationships up, but just explain that you disagree with the way things are going and no hard feelings are meant to anyone.

As a player, it becomes increasingly difficult not to fall into the idea that characters must be optimized for fighting, spell casting, or some similar aspect. Storytellers make it a near impossibility to avoid conflict of some sort, so why not be the best that you can be to win at it? Well… the answer is several fold, a character’s diversity will get him through more situations, and it may serve to keep the power gamer in all of us in check. Virtually no person on earth is perfectly suited to doing the job they choose to do. Horse jockeys must be of a small stature; however, it can be a constant battle with weight to keep them in the saddle. Some thieves are witty and charismatic, others are just street thugs. So why would real characters be any different?

As far as the dice go... well, they are just dice. No one is as lucky as the guy next to you, but there’s really nothing you can do to change your luck or anyone else’s for that matter. Many players I know would roll the dice several times before they were required to make a roll just to make sure they “wasted the bad rolls.” I guarantee this method doesn’t work for anyone.

How can a simple yet all knowing game master curb the abuse of mechanics from your own players? Firstly, don't allow them to play the character classes, flaws, and merits that stack up evenly, set them to have a specific flaw or merit that prevents the "perfect" character to be created. You have this power, use it accordingly.

Secondly, force your players to only gain levels doing things they actually do. For instance, some storytellers will only allow skill ups in skills when a player demonstrates a creative use of the skill or an extremely lucky roll that grants further insight into the skill. You can also slightly decay certain skills they don’t use or don’t show competence in with a bit of fair warning early on. I once created a personal Imperial Guard to the Queen of the realm that was a skilled fighter and competent reader of people. My storyteller at the time forced me into a series of unusual events that lead to my character becoming a mystic visionary spell weaver of sorts, and left my fighting skills rotting in the dust. While I mourned the death of my dual-wielding agile pup, I had a fantastic time delving into the character.

If it happens to be the dice, look lastly to add the element of luck or surprise, to beat good rolling: “All of a sudden, when the position of your forces looks the bleakest, reports from scouts come in: The enemy’s lead commander on his right flank was turned into a crispy donut and eaten by one of your mages, and a new surge of hope rushes into your troops. The gods must favor you as the victor today... Add (an appropriate number) to all rolls.”