Series Info...Building Stories, Telling Games #45:

Thinking Mechanically, Part 3: Characters and Resolution

by Travis S. Casey
October 25, 2002

Last time, I started talking about character creation systems; specifically, about class/level-based vs. skill-based systems. That's far from all there is to decide about character creation, however. This time, we're going to dig a little deeper — and to do that, we need to talk about action resolution.

Be It Resolved...

Action resolution is, in many ways, the "game" in "roleplaying game". A common way to describe RPGs is as "make-believe with rules". The rules prevent arguments of the "I shot you! No you didn't!" variety familiar to everyone who ever played Cops 'n Robbers or Cowboys 'n Indians.

And that sort of rule is an action resolution rule — one which is used to decide the results of an action that a character takes in the game. Early RPGs often used many different systems for resolving actions; for example, in D&D, a character might have a certain straight percentage chance of picking a lock, rolled on percentile dice. The chance of hearing a sound might be expressed as a chance rolled on a six-sided die. The chance of hitting someone in combat might be expressed as needing to roll a certain number or above on a 20-sided die, with the number depending not only on the skill of the attacker, but also on the defender's armor and dexterity.

Such a set of essentially ad hoc rules can work, but, for paper RPGs, it puts a large burden of memorization on the players. In a computer-based RPG, there's no burden put on the players, but that burden still exists for the programmers (who have to program each particular mechanic) and on scenario designers (who need a basic understanding of all the mechanics in order to properly design scenarios). In the paper RPG world, and increasingly in computer RPGs as well, most games have moved to using a single resolution system — one method of rolling dice and mixing in modifiers to determine the success or failure of actions.

An example is Third Edition D&D its system can be summed up simply: an action is assigned a Difficulty Class, which is a number indicating how difficult it is to accomplish. Higher numbers are more difficult. Characters may have things that make them more (or less!) able to accomplish actions — attributes, skills, special abilities, items, etc. These are assigned numbers — positive numbers if they make it easier, negative if they make it harder. These numbers are totaled up and added to the result of a twenty-sided die. If the total equals or exceeds the Difficulty Class of the action, the character has succeeded; otherwise, he or she has failed. The amount by which the character succeeded or failed may be used in further calculations about what happens.

Looking at this more closely, we can break action resolution down into three phases — what I like to call the three R's of mechanics: Reduction, Resolution, and Representation. Let's take a look at each of these.

In the Reduction phase, a situation in the game is reduced to numbers that will be used to resolve it. Some of these numbers may be ones associated with a character, such as strength or skill with a weapon. Others may be associated with objects in the game (weapons, armor, etc.), conditions (darkness, rain), approaches (all-out attack or cautious attack), or with meta-game influences (things that exist at the player level, such as whether a player has chosen to spend "luck points" on an action).

These numbers are then used in the Resolution phase. Here, the numbers are used in a formula, often with one or more randomly-generated numbers thrown in. The result is one or more numbers which describe how well the character accomplished the task.

In the Representation phase, the numbers generated in Resolution are interpreted into game-world terms. This involves generating descriptions of what happens, and may also involve generating more numbers, either randomly or calculated from numbers generated in the Resolution phase.

To put it another way, each phase answers a question:

What factors influence this action, and how important are they?
Does the action succeed or fail, and how well or badly?
What happens as a result?

In Third Edition D&D, then, the Reduction phase produces a Difficulty Class for the action and the bonus that the character will use. Resolution consists of rolling a d20, adding the bonus, and subtracting the Difficulty Class, to obtain a single number that indicates a degree of success or failure. The Representation phase sometimes simply uses the level of success or failure, and sometimes involves rolling more dice — e.g., the damage roll in combat.

One thing that should be noted is that action resolution can be iterative; that is, the output of one action's Representation phase may include numbers that can be used in another action's Reduction phase. In many RPGs, such a setup is used for resolving long-term tasks — the task is divided up into multiple actions, and previous actions influence the results of the next action. This method is also used for actions that exist to help other actions — e.g., a feint in combat may generate a bonus to be used in the character's next combat action.

With respect to computerized RPGs, including online ones, it's worth noting that the Resolution phase can generate multiple values. Only a very few paper RPGs do this — one example is the free RPG OtherKind. In it, multiple dice are rolled in the Resolution phase, which are then assigned to different aspects of the action in the Representation phase. In a computerized RPG, it's easy to generate a large number of values in the background and apply them — remember, though, as I mentioned two columns ago, that you don't want to go overboard — even if the players don't need to understand the system, scenario designers and other folks do need to.

(There are other ways to break down action resolution as well... we'll be getting to at least one more in a future column.)

Back To Characters

We started out talking about character creation, didn't we? Well, from a game-mechanical standpoint, the purpose of a character creation system is to assign numbers to describe the character, which will later be used in action resolution — either in the Reduction phase, or in the Representation phase. Since paper RPGs use dice and need to have reasonably simple math, the numbers are usually of a size convenient for people to work with "in their heads" and which will mesh well with whatever size of dice are being used. In a computerized RPG, however, no such limits need apply; you can do things that would never work in a paper RPG, such as use a linear scale for strength, with 1 being the strength of an ant.

Every new system takes getting used to. Even for experienced gamers, it can take playing a game a few times before one really gets a feel for what a certain set of ability scores, skills, etc. will let a character do. This can especially be a problem in the freer point-based systems — the freedom to give a character whatever skills one wants can easily lead to either taking too narrow a set of skills and not having skills that the character needs, or to taking too broad a set of skills, with the result that the character isn't very good at anything.

Template systems, mentioned in the last column, can help with this; at the very least, having a selection of pre-made character templates to look at can give a player an idea of what skills and skill levels certain kinds of characters can be expected to have. The game designers, however, must be careful to create good, workable templates — a bad template will only serve to steer players wrong and frustrate them.

But there's more to life than just numbers! The numbers associated with a character may be the most important things from the point of view of game mechanics, but a character is more than just the mechanics... and that's what we'll be starting to delve into next time. Which is odd, since this is still a series on mechanics, but bear with me...

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