RPG Design Patterns

Provide the niche-protection benefits of the Class pattern while allowing players flexibility in customizing their characters along with the ability to gain new abilities as game play progresses.

Class Path, Career Path, Life Path

Class, Loose Coupling, Template, Traits

The Class Tree pattern is closely related to the Class pattern and is based on the fundamental concept of classes, but adds flexibility by allowing a player to select multiple classes at different points in his character’s career. The basic class pattern allows a character to gain more than one class in some games, so in this regard the class tree is not unique. What distinguishes the Class Tree pattern from the basic Class pattern is that Class Trees allow career options to increase as play progresses. That is, some classes are unavailable to a character until certain conditions are met. How those conditions are satisfied varies from game to game, but a class that provides more benefit than another will generally be more difficult to attain. Since character abilities tend to increase as more classes are gained, the more classes a character has, the greater the number of classes for which he qualifies. If a character can only obtain a limited number of classes, though, the player is forced to make important decisions concerning his character’s career.

When a new class is obtained, it expands the character’s in-game options through increased skill sets. As he gains each new class, the character changes qualitatively. This can breathe “new life” into a character as the player has new potential activities to explore. It also has the benefit of requiring the player to make a statement of what capabilities are important to his character, because the classes chosen must be made at the expense of other career options. Since the options branch and increase in number over time, advancement opportunities can be thought of as a tree structure.

The Class Tree pattern can be used in games when you want to

1. Simplify character generation by reducing the number of decisions that need to be made by players,
2. Increase flexibility in character design over a basic class system,
3. Provide niche protection for different “types” of characters,
4. Allow expansion of character skill sets as play progresses.

If niche protection is unimportant to your game concept, you might want to consider using the Template or Traits patterns instead.

The Class Tree pattern puts a lot of work on the game designer’s shoulders, because it requires him to write up detailed descriptions of a fairly large number of interesting classes pertinent to game play.

Because of the potentially bewildering array of class options demanded by the Class Tree pattern, character generation for beginning players can become more complex if the players must assess their preferred choices from all those available. This conflicts with the basic Class pattern’s goal of making it easier for beginning players to get characters up and running quickly. For this reason it is best to keep the number of “starting” classes to a fairly low number and partition them from the other class options for easy perusal. Another option is to make the choice of class random, so beginning players do not need to make informed decisions. They just roll dice and take what they get. Gamers wanting a great deal of control over their character’s makeup are likely to find this solution to be unsatisfying, however.

When implemented properly, the Class Tree pattern becomes part of the game’s reward system. Players will tend to focus their characters on attaining particular “advanced” classes that interest them and often get a thrill when their characters finally gain them.

As play progresses in games using the Class Tree pattern, the characters’ list of in-game options expands as the number of abilities bestowed by their growing class list increases. Because of this gradual but punctuated enhancement to character effectiveness, players tend to find renewed interest in their characters as new play options become available.

The Class Tree pattern has many of the same implementation concerns as that of the basic Class pattern. You will most likely need to have some limitation on the number of classes that a character can select, so that no character is capable of gaining all classes and thereby negate the niche protection features of the pattern. One way to do this is to have a resource which players can use to buy their classes at some pre-defined “cost” (see the Resource pattern).

The niche protection characteristic of the Class Tree pattern is one of its most important features, so care must be taken to ensure that the skills of one class do not trespass too far into the realms of other classes. This can be difficult at times, because the sheer number of classes that must be written to make the Class Tree pattern sufficiently flexible make some overlap between classes virtually inevitable. To mitigate this problem, you can have different classes that overlap in their skills make-up have other important differences. If the Skills Rank pattern is being used, one way to do this would be to make the overlapping skills have significant differences in the cost needed to gain ranks, even though the skills themselves are similar.

Since a class tree necessitates some kind of interaction between classes and must somehow allow advancement from one class to another, some means of identifying what classes are available to a character at any given time is needed. If care is not taken concerning how these options are presented, problems in future game expansion can arise. For example, if you decide to write and release a supplement of new class options after the game’s core rulebook is released, you may encounter difficulties in allowing characters to take advantage of the new classes since the core rulebook has no knowledge of their existence. For information on how these problems can be mitigated, see the Loose Coupling pattern.

The following might be an example of a class in a game containing Caribbean-style pirates:

These flamboyant swordsmen travel far and wide in search of adventure. Many stories tell of swashbucklers swinging on chandeliers to quickly rescue maidens. They relate how these characters leap from ship to ship to combat rivals with swordplay. Although many swashbucklers constantly break the laws of established governments, all seek merely to have a good time. Jovial to the end, swashbucklers often swill rum, mead, or wine when engaged in combat and laugh heartily at their own mistakes in battle.

Attribute Requirements

Agility 2, Perception 2

Prerequisites

The character must be able to swim (via the Swimming gift) and must have attained 8th rank in wielding Sabre, Cutlass, or Foil.

Gifts

Acrobatics, Dancing, Etiquette, Holding Liquor, Speaking Foreign Languages

Skills

Climbing Walls (+1), Disarming Opponents (+3), Florentine (+3), Inspiring Loyalty (+2), Navigating (+2), Raising Morale (+2), Seamanship (+1), Weapons Resourcefulness (+3)

Weapon Proficiencies

Wielding Sabre (+2), Cutlass (+2), and Foil (+2)

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Dungeons & Dragons v.3.5 has 11 basic classes, including Barbarian, Bard, Cleric, Druid, Fighter, Monk, Paladin, Ranger, Rogue, Sorcerer, and Wizard. After a character has advanced sufficiently in “levels” (see the Level pattern), he has the option of obtaining any of a number of “Prestige Classes.” The “Dungeon Master’s Guide” lists only 16 prestige classes including Archmage, Blackguard, and Hierophant, but there are numerous D&D supplements that provide a host of others. Each prestige class provides a list of “Requirements” needed to attain the class. The basic rules allow characters to progress based on the total number of levels of all classes obtained. A 10th level fighter/7th level wizard is treated as a 17th level character overall. So, he would not progress to his next level until earning the experience necessary for an 18th level character. So, the system discourages having any character branch out into too many classes.

Warhammer Fantasy Role Play has 4 broad class categories of Warriors, Rangers, Rogues, and Academics. Once a player selects one of these categories, he rolls randomly to determine which of the “Basic Careers” associated with that broad class that his character starts with. The game has 63 “Basic Careers” and 36 “Advanced Careers,” most of which have “Career Exits” that specify which careers are available as advancement opportunities to a character that currently has that career. When a player decides to have his character take a career exit, he must spend an appropriate amount of experience points to do so. When he does, his previous career is over and his new potential “Career Exits” are those associated with his new career. A new career gains him new options but loses old ones. (Perhaps this would be better described as a “Class Vine” rather than a “Class Tree.”) Each career provides a list of skills and pre-defined limits on how far a character can progress in his abilities while practicing the career.