Background-Based System

The method of Character Customization by building the character from the ground up iteratively: for each consecutive stage of life - often from circumstances of birth - choose a pre-set bundle of abilities and traits expressed in statistics, either fixed or with minor variations ("2 ranks of any skills in group X"). The presence of background building may range from optional background "packages" that set the general tone to stage-by-stage selection of bundles that define everything.

It supposed to have (implementations and their specific uses may vary) several advantages:
 * Fast: It's important for Game Masters who need to churn out NPCs without making them faceless clones.
 * Intuitive: Character creation mechanics is encapsulated in small manageable pieces that make sense on their own.
 * Promotes roleplaying: At least, the characters are likely to be better grounded in the setting if they are for most part explicitly defined by it.
 * Not too prone to Min-Maxing: Extreme statistics are possible only as much as allowed by an extreme set of paths.

Some choices may have prerequisites, but each stage allows selection of multiple variants. Thanks to Combinatorial Explosion effect, limited choices may add up to considerable variety of the results.

This method can be used either standalone or as a layer over others, making a more free-form core Point Build System or Class and Level System more strict and less abstract in an attempt to combine benefits of generic systems that avoid arbitrary limitations and simulation model that can (and often needs to be) fine-tuned for a specific setting. It by definition limits versatility of free-form systems, but can be made exactly as flexible as the designer wants it to be. Since there are so many possible variations, randomizing them is an obvious and tempting option; as yet another form of "random stats vs. mostly-deterministic campaign needs" conflicting requirements, the optimum is subjective (for the specific group or Metagame).

Prestige Class concept approaches the same general goals (or at least supposed to) as customized add-ons to the set of more generic base classes.

Tabletop Games

 * Burning Wheel has "Lifepaths". It wasn't the first, but worked well enough to become the Trope Maker.
 * Take on Rules RPG blog has [//takeonrules.com/tags/lifepaths/ a few fan-made Lifepaths], mostly converted from Eberron and Warhammer Fantasy Roleplay. Can be curious for comparison of how things work in different systems.
 * Fading Suns in later editions has optional "Lifepath System". A web supplement and mention of the system being updated in new core books was in free downloads on FASA site.
 * 1) Formulate concept
 * 2) Choose faction and role. Faction gives 1 Blessing and 1 Curse, often with Suggested Benefices (that have to be purchased for points) and/or sometimes Benefice Restrictions (limits of how many point can be sunk into something).
 * 3) Choose history: Upbringing, Apprenticeship, Early Career (each stage gives 1-2 steps of choices)
 * 4) Spend extra points
 * The original Traveller had an extreme version of background generation: it simulated a Player Character's entire young and middle adulthood, complete with a career with dice rolls before you got to your first moment of play, resulting in the skills you needed to survive, the savings you accumulated (if any), and any equipment you'd acquired. One bad side-effect: It was possible for a character to die during character creation, before you ever got to play him.
 * Stars Without Number
 * Original Edition has an option of character generation with skill packages: generic Background Package of 4 skills + class-dependent Training Package (8 skills for Expert; 6 for Warrior, 4 for Psychic; expansions mostly use unified packages with common and "extra" skills marked as such). Each raises a given set of skills, some give advantages of giving cross-class skills without spending extra points or overlapping sets, which raise skill cumulatively (it's better than raising them via point-buy due to diminishing returns: the point cost for raising 1 skill to "professional" level is the same as raising 3 to "trainee"). And of course thematically close packages tend to overlap more (e.g. with Soldier background, Mercenary training allows to improve all 4, any other Warrior path up to 3). All choices have "Adventurer"; this gives 1 (for background) or (training) less skills, but some are completely arbitrary and the rest selectable from a wide range.
 * Sandbox magazine #2 offers a full Lifepath expansion, with generated important Life Events and random flaws and perks.
 * Revised Edition only has plain background packages (with options to pick, take standard advances or roll — the latter potentially the most advantageous, as it allow attribute increases and doubled skill picks). But it also other ways of customization, such as Foci ("character concept" packages that usually give one bonus skill and a special ability using it, which can be "upgraded").
 * Twilight 2000 offered the ability to customize a character's entire background, choosing hobbies, career and education for the character throughout his entire lifetime. Each choice allowed the player to increase specific skills related to that choice, giving a character who has both a history and physical/mental attributes to match that history.
 * Warhammer Fantasy Roleplay has careers/mini-"character classes" like Poacher or Alchemist's Apprentice, or Scout, each with its own mechanical features, unique starter equipment, set of advances and "exits" (set of other careers to which the character may switch).
 * Warhammer 40,000 Roleplay series use the homeworld or origin and other factors (varying per game line) to determine starting traits and abilities.
 * Dark Heresy adds the starting set from Career (Character Class), possibly with Alternate Ranks, Background Package (unusual origin or early occupation), Elite Advance Packages (paths opening by story circumstances, such as surviving possession and being exorcised or being an active participant of some secret society) and Cell Directives (specific Ordo or task group training) for Acolytes of the Inquisition, and then there's mechanics of Elite Advances (unique opportunities taken with GM's case-by-case approval, like learning a relevant skill while working closely with someone who uses it).
 * Rogue Trader has a graph for "Origin Path" (that can be traversed from either end, of course): Homeworld - Birthright - Lure of the Void - Trials and Travails - Motivation - Career, with each step giving 2-3 choices depending on the previous . On an "Intersection" (the same option chosen for more than one character in the party) the players may generate shared background element (e.g. Vengeance applies to the same enemy). The later sourcebooks added substitute options, Lineages (extra background options not linked to the path and with XP cost, much like Background Packages, that represent clan- or occupation- related traditions), and used the same approach in "Nemesis Path" for opposing NPCs and "Ship and Warrant Path" for the Rogue Trader dynasty.
 * Only War runs with military unit perspective, so the starting advancements and set of Aptitudes (profile of advancement costs) are defined by the regiment's origin, basic type, commander's attitude (serving under a Hot-Blooded lead-by-example commander, rigorous military scholar with little initiative or glorified mailman is not going to be the same), Training and/or Equipment Doctrines. Then there's class (guardsman or one of support specialists) and Speciality (which occasionally can be changed, but not often and not for everyone).
 * Dungeons & Dragons
 * 3.5 Unearthed Arcana options include Background generation, tying in with related options (reputation and contacts).
 * Forgotten Realms had local kits introduced in AD&D2 sourcebooks Wizards & Rogues of the Realms, Warriors & Priests of the Realms and Demihumans of the Realms.
 * 3.x FR sourcebooks (starting from Campaign Set, Races of Faerûn and Player's Guide) generalised it to "Character Region" (in this context, not just geographical area, but a specific culture there) which adjusts the rest of generation: known languages, specializations for skills, Preferred Classes, Bonus Equipment and flavour Regional Feats. The implementation was flawed, however. Both of the latter were accessible for characters with Preferred Classes in 3.0, in 3.5 Preferred Class was removed and feats limited to 1 at 1st level ).
 * 5th Edition finally makes this standard for character creation. Each background gives you various proficiencies (all give 2 skills, some give language and tool proficiencies as well), some basic items and a perk that varies wildly in usefulness. Most gain instant respect from or knowledge of some part of society (like commoners, priests, nobles), but Hermits just gain knowledge of a location and Guild Members have to pay for their perk of the guild covering certain costs.

Video Games

 * Darklands has complicated background-based character creation, where choosing your character's upbringing and career allowed ending up with extremely varied results. This naturally takes more time than random or point-buy, but results in a character that has a reason for his particular stats.
 * Liberal Crime Squad makes the player answer a series of chronologically-arranged multiple-choice questions on character creation, starting from birth and ending in the character's present circumstances at the start of the game.
 * System Shock 2 character generation gives 3 fixed stages of career path, 3 choices on each. Each pass gives a piece of background with corresponding stats boost and skill or psionic power.