Keeping it rolling in the "Fluff" department, I figured I'd do a little bit of overview about something called the "Core Mechanic". Every system has it, and they all have different takes on it. The Core Mechanic, in a small nutshell, is the bit of the rules which governs the main ability tests and usually also combat. If you are trying to do something, you almost always use the Core Mechanic. So, with that being said, I'd also like to make a mention of the three basic types of Core Mechanics out there.
As a quick note: I make reference to several different types of dice in conjunction with the three Mechanics, but there is no direct correlation between Core Mechanic method and die type. I'm just spouting off the top of my head the different dice that I can think of as being used for that method.
The first one is what I would call "Roll and add". This is what the most well-known RPG,
Dungeons and Dragons, makes use of. It's also the most prominent and popular mechanic in RPGs. Essentially, you roll a die, or a few dice, and then add any appropriate modifiers, trying to beat a difficulty rating for the task. For instance, many rolls in the latest edition of D&D take a 20-sided die (1d20), and add in half of your level, then a modifier generated from the appropriate character attribute (such as Strength or Wisdom), and then any other bonuses, such as weapon proficiency or skill training. The 20-sided die is the most common, although some games also use two 6-sided dice (2d6), three 6-sided dice (3d6), or even a 10-side die (1d10).
The second type, which is related to the first, is the "Roll under" mechanic. Found in systems like
The Generic Universal Roleplaying System (GURPS), it takes a somewhat different approach to the subject. Instead of trying to roll higher than a set difficulty, you try to roll
lower than a certain number, which corresponds to your skill level in the task. The difficulty of the task isn't reflected by a "difficulty level", but rather by negative modifiers to your skill level. Although GURPS uses three 6-sided dice (3d6), other systems use a 20-sided die (1d20), although one game has a 12-sided die (1d12).
My favorite Core Mechanic, though, is the "Dice pool" mechanic. The
World of Darkness system is one of the best-known dice pool RPG systems. You roll a certain number of dice, and then compare each individual die to a specific target number. You count how many successes were scored (usually by rolling above the target number on a die), and the number of successes determines how well you did a task. WoD uses 10-sided dice (d10s), and another common size is 6-sided dice (d6s).
At this stage in the game, I'll note that not every game fits neatly into these categories. The RPG
A Song of Ice and Fire, from Green Ronin productions, uses a dice pool but its primary mechanic is "Roll and add". Wushu Open uses "Roll under" as a means to qualify die rolls, but it's a "dice pool" mechanic. These three categories, however, showcase different strengths and weaknesses of their respective approaches to character power and randomness. Sometimes, it's not even a question of strength versus weakness, so much as the appropriateness of one approach to the feel of the game.
The "Roll and add" and many "Roll under" systems tend to have a markedly different way of approaching character than "dice pool" systems, interestingly. Because the former methods deal with trying to beat/roll beneath a specific target number, there is often an increasing "bonus" attached to the die rolls. The obvious example here is the classic D&D paradigm, where all of your rolls increase as you level up. As you increase in expertise, you get to the point where more and more challenges are automatically covered by the bonus. In "dice pool" systems, there tends to be a far greater concentration of tasks that are some sort of challenge at any level, because nothing can be guaranteed.
As a side note...I can't believe it, it's the end of 2009 already. Good grief! Stick around, because in a couple of days, I'll be releasing a brand-new feature for a brand-new year!
