In Real Life, the human brain acquires new knowledge and puts it to use via a spectacular cascade of electrochemical reactions taking place across a heavily networked biological cell grid. Learning and improving one's skills is a continuous, life-long process, while expertise in one field often proves unexpectedly useful in other, seemingly unrelated domains. But complex neuroscience has no place in video games, because a) it violates the Rule of Fun, b) programming such a system is next-to impossible, and c) it runs a high risk of spawning a murderous AI on your computer.
Instead, tabletop and video games — particularly Role Playing Games and games with RPG Elements — narrow the areas of human knowledge down to a handful of quantifiable "skills" that are relevant to the plot at hand and whose advancement and effects can be defined in terms of gameplay mechanics. At the start of the game, the players are handed a list of these skills and a few "skill points" to distribute among their characters' abilities, with more points awarded later on for completing the game's objectives. Once a skill is learned, the character (usually) can never forget it, except deliberately and with a full points refund.
There are two common ways to define character skills in the Game System terms: skill scores (a.k.a. "skill levels") and perks (a.k.a. "feats" and "traits"). Following table outlines their main differences:
|Improve basic in-game actions||Unlock new moves and unique bonuses|
| Can be leveled up multiple times |
(anywhere between 3 and 100)
| Usually cannot be leveled up, |
although some perks may be upgrades of others
| Skill levels have index numbers, or |
generic labels ("novice", "trained", "master")
|Each perk or upgrade has a unique identifying name|
|No skill levels are technically needed to use basic actions||Active perks must be learned before using them|
|Follow a linear improvement progression||Often form branching "skill trees"|
| Each skill level "unlocks" the next one, but |
they may be capped by another stat or Character Level
| May have prerequisite perks, character levels, |
skill and stat scores
| Improved by spending Tech Points, by repeated use, |
or automatically with each level
| Usually acquired by spending Tech Points, |
occasionally through Nonstandard Skill Learning
|Higher skill levels may cost more than the lower ones||More advanced perks may cost more than the basic ones|
Skill scores and perks often coexist side-by-side, mixed-and-matched in a myriad of ways, and many games (especially contemporary RPGs) go out of their way to blur the line between the two.
Video game examples:
- Ghost 1.0 has five skill trees where the player can spend skill points to unlock various perks. Each perk provides an active or passive benefit, and also increases an attribute associated with its corresponding tree: Chassis perks increase Ghosts max HP, Boogan perks increase her maximum ammo, Jacker perks increase Jackers hacking speed, Ghost perks increase the damage output of possessed robots, and Nakamura perks increase the drop rate for health kits.
- Uncharted Waters: New Horizons features a combination of seven skill scores (ranging from Leadership, through Knowledge, to Swordsmanship) which increase your performance as a fleet captain, and five perks: Celestial Navigation lets you auto-sail to any known port, Cartography allows you to sell maps, Gunnery drastically improves combat performance, Accounting tells you best places to sell your goods, and Negotiation lets you haggle for better prices.
- Final Fantasy X is famous for the Sphere Grid and its potential flexibility, with nodes that either increase certain stats or provide a new active ability. Each node requires the appropriate sphere to activate it and certain areas of the grid are separated by locked nodes of various levels. The original version have a somewhat linear progression path for each character(with the exception of Kimahri, who starts in the center with access to almost every other character-specific grid area) giving them a more pre-determined role early on, but can access other parts once they complete their paths or unlock the lock nodes separating each area. The International version adds a second grid layout, Expert, in which every character starts at the center of the grid and are able to go anywhere they wish, though overdrives and weapons remains unique to each character.
- The Crystarium system Final Fantasy XIII consists of class-and-character-specific (mostly linear with minor sideways branching) perk trees, whose nodes have increasing "crystogen point" costs. Most nodes provide bonuses to either Strength, Magic, or Health, but some unlock class/role-specific moves. In Final Fantasy XIII-2, each character has only one linear "perk tree", but its nodes are technically empty slots where the player can place perks (bonuses or abilities) of any of the six available classes (up to 99 per class) by investing crystogen points.
- Kingdom Hearts 3D: Dream Drop Distance has Spirits and their Ability Link system. By training or fighting alongside your Spirits, they gain Link Points which are used to unlock skills or increase Sora and Riku's stats. Each Spirit has a different link board, granting different skills and perks. Most passive skills are only available to you if your Spirits have them on their board.
- In the remake of Nocturne (RPG Maker), the two main playable characters don't level normally. Instead, they stockpile experience and spend it on learning and upgrading skills from a skill tree. Upgrading skills provides extra stats while learning new ones don't, meaning the player has to strike a balance between learning and upgrading to get a versatile, yet strong party. The catch is that spending a certain amount of EXP forces the character to level up, which can prevent the player from meeting Brave Clear conditions.
- In Capella's Promise, characters can spend SP to learn and level up different Specialties, allowing them to learn new skills. However, each time a Specialty's level is raised, the cost for all specialties go up to discourage too much skill diversity.
- In Forever Home, characters can spend PP to learn and upgrade skills. The complete list of skills aren't available until the characters pass experience level thresholds though.
- Star Wars: The Old Republic features a two-fold upgradable perk system, split into class-specific Abilities and Prestige Class-specific Talents. Abilities are mostly active powers that can be purchased from or upgraded by class trainers for credits after reaching certain levels. Talents are mostly passive bonuses with some unique active powers thrown in that form three loosely connected specialization-specific trees. Each level beyond 10 gives you a Talent point to buy a new talent or upgrade an old one. In addition, there are the Crew Skills, which allow crafting and resource gathering and are improved by using them, though you are limited to three at any time.
- Star Trek Online
- Skills and traits are selected by the player and provide mainly passive bonuses in combat. Your skills increase the potency of your ship and away team powers (for example, Starship Graviton Generators improves gravity-related bridge officer powers such as Tractor Beam and Gravity Well). Attributes apply only to the character who has them. Individual species have inherent attributes (e.g. Bajorans get a bonus to HP heals on the ground), and player characters can select from a pool of additional traits (bridge officers have the latter built-in), some of which are built-in and vary by class, while others unlocked as lockbox prizes or by leveling up crafting schools. The number of selectable traits you can equip increases from three at first level to nine at level 60.
- Completing kill and damage accolades provides small passive bonuses to damage and toughness. For example, destroying 200 Borg ships and getting the "Nanoprobe Immunity" accolade gives a 2% damage boost against Borg ships, and taking 15,000 kinetic damage with your captain (primarily taken from melee attacks) for the "Punching Bag" accolade gives +2 to your away team's kinetic damage resistance.
- The Reputation system, completed by spending marks earned by playing PVE content. Each Reputation has four space perks, four ground perks, and one active power (as of deason 9 a total of four of each, in any combination, can be active at any time). They also include projects to craft unique gear and stores where you can buy special weapons.
- Tier 5-Upgraded and Tier 6 starships include the "Starship Mastery" mechanic, which unlocks four tiers of perks specific to that ship as you earn XP while flying it. Additionally, unlocking Tier IV Starship Mastery on a T6 ship grants access to a unique starship trait that is available while flying other ships. Four starship traits can be active at a time.
- Dungeons & Dragons Online still uses the same Skill-and-Feats system as its tabletop counterpart but has diverged to include 'enhancements', which are like mini-perks that you can select with points earned at certain points between character levels.
- World of Tanks has skills and perks available for tank crew members on reaching 100% of their primary qualification. Skills take effect immediately while perks only take effect on reaching 100%. Most provide major benefits, with some, such as Sixth Sense for the commander (alerting when spotted, with three seconds delay), being considered One Stat to Rule Them All, while others are considered a Dump Stat due to Crippling Overspecialization from being only useful on some tanks or in select circumstances, being made redundant by equipment or provide too little benefit to begin with.
- The Fallout series has a skill system based around seven static attributes (ranging from 1 to 10), skill scores (measured in percent and upgraded at every level), traits (essentially perks with both advantages and disadvantages that you pick at the beginning of the game), and learnable perks (which you can take every three levels). Fallout 3 took out traits and made perks more common (every level), then Fallout: New Vegas added them back in while lowering the perk rate (every other level). Fallout 4 drastically alters this, fusing perks and skills into a perk tree similar to Skyrim.
- The Elder Scrolls:
- The first four games in the main seriesnote all have similar variations of a Class and Level System, with a few quirks varying by game. Oblivion, while still staying in line with the series' traditional system, adds Perks for the first time, which are unlocked by reaching certain levels in skills: e.g. a Power Attack at Blade 25, no shield wear-out at Block 50, jumping off water surface at Acrobatics 100, etc.
- Skyrim overhauls the series' system, doing away with classes and attributes entirely while moving into the territory of this trope. It loosely borrows the Perk system of its Bethesda Fallout sister series, expanding the available perks to an entire tree (one per skill score); perks now have prerequisite perks and corresponding skill score levels and can be bought and upgraded with perk points (gained with every Character Level up) once unlocked.
- Dragon Age:
- In Dragon Age: Origins skill scores ("skills") and perks ("talents" and spells) exist in parallel, although the latter are much more important. Eight (11 in Awakening) skills can be leveled up four times, providing passive bonuses to anything from persuasiveness, through pickpocketing, to combat efficiency. Talents, meanwhile, are distinct moves, auras, passives, and upgrades grouped into "trees" of three (four in Awakening) linear four item-long branches (mages get spells instead of talents but they work the same way). There are also class- and specialization-specific perk trees. In addition to being part of a skill tree, new perks have stat and (in case of weapon talents) skill level requirements. Talent points are gained at every level, and skill points, every three (two for rogues) levels.
- Dragon Age II does away with the skills but expands the talent trees to branch out more.
- Dragon Age: Inquisition follows the DA2 model with combat moves, but complements it with the so-called "Inquisition Perks", which represent the special services offered by the title organization (of which the Player Character is the boss) as it grows in power and influence. These range from unlocking additional dialogue options, to improving basic in-game actions (like letting all rogues in the party pick tougher locks), to combat bonuses, to crafting resource boosts.
- Alpha Protocol uses a system similar to Mass Effect in that your skill points both improve your proficiency directly and, at predefined points along the tree, grant access to special actions such as Bullet Time or HUD indicators as to enemies' location, disposition, and facing. Various other perks are granted for fulfilling story conditions.
- Being based on the d20 System, the Knights of the Old Republic games feature both skill scores ("skills") and perks ("feats" and "powers"). Skill scores range from hacking, through persuasion, to first aid and are upgradeable multiple times per level (skill points gained depend on the class and the INT stat). General feats (mostly combat moves, but also skill bonuses) usually come with one or two upgrades and can be taken every other level (depending on the class). Powers can only be learned by the Jedi at a rate of one per level (more for some classes). Powers associated with the Light or Dark Side of the Force additionally gain bonuses from your Karma Meter standing.
- Pillars of Eternity has Skills, Abilities, and Talents. Each character earns six Skill points each level, and every new skill level costs one point more than the last; however, different classes and backgrounds give free levels in certain skills at character creation. Apart from improving basic in-game actions, Skills are used alongside Attributes in dialogue and scripted interactions. Abilities are class-specific perks that can be taken at every odd Character Level, while Talents are (mostly) class-independent perks earned at every even one. Abilities and Talents can be passive boosts, active abilities, or modal effects. Talents are further subdivided in Class (class-specific bonuses), Offensive (improve attacks), Defensive (improve combat defenses), and Utility (everything else). Some Talents can only be acquired as rewards for completing certain side quests.
- The Witcher has an expansive skill tree focusing on four primary attributes (Strength, Dexterity, Stamina, Intelligence) and talents (Signs, steel sword, silver sword). Talents have a prerequisite attribute (i.e. you cannot learn lvl.3 "strong" sword style without lvl.3 Strength), and the Signs additionally have to be unlocked at Circles of Elements first. Individual perks are leveled (bronze, silver, gold), as are skill points (silver points are earned from level 15 onwards; gold ones, from level 30). Lastly, there are some perks that cannot be learned normally but have to be unlocked by drinking unique "mutagen" potions.
- Diablo II features a hybrid skill score/perk system, wherein each class has three unique skill trees consisting of several tiers of perks. Individual tiers are unlocked one by one at certain character levels, after which any number of skill points (gained at each level and from some quests) can be invested into any unlocked perk, increasing its efficiency and often giving bonuses to more advanced perks derived from it. On a side note, Diablo II has one of the earliest implementations of the aura-type perks (with its Paladin class).
- Mass Effect has a hybrid skill score/perk system wherein "talents" encompass both passive (armor, weapon) and active (biotic & tech attacks) skills. Talents can be leveled up multiple times, increasing their efficiency and unlocking additional perks and even further upgradeable talents at certain levels (forming an implicit skill tree); Charm and Intimidate talents are additionally capped by your current Paragon and Renegade scores, respectively. Mass Effect 2 and Mass Effect 3 replace them with "powers"—active combat skills, which are essentially perks with up to five (mutually exclusive at level 4+) upgrades available for each of them. Most talents and powers depend on the character's class and are available from the start, but some are only unlocked after certain story events.
- The original Deus Ex features both skill scores and perks (dubbed "augmentations"). Skill scores are upgraded using skill points acquired in small heaps by completing objectives, have four levels (Untrained, Trained, Advanced, Master), and improve your performance with different types of weapons, or non-combat actions (lock-picking, electronics, medicine, etc.). Augmentations are picked up as items on missions and implanted into Denton's body slots, giving him new abilities, and can likewise be upgraded up to level four with "upgrade canisters".
- Deus Ex: Human Revolution merges the two subsystems from the original game: you don't have any skill scores anymore, but still gain small heaps of "Praxis Points" here and there, with which you directly unlock individual augmentations from the Tech Tree (justified by that all augs are already built into Jensen and only need to be activated).
- Path of Exile has an enormous perk tree consisting of 1300 nodes available to each class, although all nodes are passive bonuses (active skills are instead imbued into items). Furthermore, a majority of nodes are unspectacular permanent bonuses to one of the character attributes (strength, dexterity, intelligence), but buying them is required to get to the juicy, named perks that provide significant combat advantages. In addition, there are also slot that lets you socket Jewels into it, which essentially work as craftable passives. Unique Jewels can interact with or modify the skill tree, such as converting one stat to another within a radius to another or grant a marginal bonus if enough of a certain type of node is allocated within radius.
- Divinity: Original Sin has a complex skill system containing skill scores, two different kinds of perks, and active powers. The Abilities (skill scores) are improved by investing points that you get (a steadily growing number of) at every level. Talents are a type of perks that have prerequisite Ability levels and can be learned every four levels from the third onwards. Traits are "Personality Powers"—small bonuses granted for consistently role-playing Player Characters in dialogue (e.g. a Romantic character has a chance of finding treasure anywhere, while a Materialistic one gets a Crafting skill bonus). Finally, Skills (active powers) are spells and combat techniques learned from books; they have prerequisite character levels and a character can only learn a number of them limited by the corresponding Ability level (unless it's maxed out, then there is no cap on Skills).
- Increasing skill ranks in the later Might and Magic work something like a perk system — skills can be made better by putting more skill points (which are — mostly — gotten by levelling up) in them (increasing dependent numeric aspects) or by being trained to a higher rank (Expert, Master, Grandmaster) if you fulfil the requirements and have the money to pay the trainer. What a higher skill rank does depends on the skill and the game, but several do give new abilities (Master Bow in VII makes bow fire two arrows per attack, Grandmaster Dodge makes the skill usable while wearing leather armour...), in line with this trope.
- Kult: Heretic Kingdoms uses both skill scores and perks in parallel. Alita has four basic statistics (Melee, Ranged, Magic, and Speed) which are rated with letter grades (B+, C-, etc.), but also as Attunements which grant specific bonuses (better chance of critical hits, more loot, etc.). Attunements are earned, but are also associated with equipment.
- Tyranny has skills, which are increased by use or increasing the associated attributes at level-up, and talents, one point of which are gotten every level and which are divided into trees.
- No One Lives Forever 2 includes a skill score system that represents various aspects of being a super-spy (stealth, marksmanship, gadgets, etc.). Each skill score can be upgraded four times, giving various passive bonuses to the respective basic action (hiding, shooting, breaking codes, etc.). Each level costs progressively more skill points, which are obtained from completing missions and finding manuals scattered throughout the game.
- The Jedi Knight series features a number of upgradeable Force Powers. In the first game and Jedi Academy, you gain skill points after every mission (first game gives bonus points for finding secret locations, while JA has optional missions to gain extra points) and can spend them on any power you want. In Jedi Outcast, on the other hand, force powers are upgraded automatically according to a fixed progression after every mission (you can still distribute points freely in the multiplayer, though). The powers are further subdivided into Neutral, Light, and Dark, and in Academy, your mentors will have comments if you prefer one Side over the other.
- Payday 2 has skill trees and perk trees, which are your only source of special inventory items (Medical bags, ammo bags, mines, turrets, and hacking devices) and passive abilities and some stat boosts. Most of these skills are passive, triggering when you interact with something or shoot / get damaged in a certain way, while others increase your stats. The highest-level skills are game changers, but some experts recommend evenly spending skill points across all skill trees. Most perks increase your stats, each tree focuses on a specific stat (Health, shields, speed, etc.), the perk tree inventory item allows you to suit up from clothing to kevlar, and only one perk tree can be selected at any time. The main difference is that skills are available at higher levels but must be paid with in-game cash to be activated, while the perks are permanently unlocked through earning a LOT of experience points, even if the character is at the level cap.
- In XCOM: Enemy Unknown, each soldier can select one of two perks at every rank (which is basically a disguised XP-based Character Level) except Rookie, Squaddie, and Major (only one perk is available at each of the latter two). The perks are usually split between two core functions of a class: Assault chooses between offensive and defensive perks; Sniper, between shooting more precisely and more often; Heavy, between More Dakka and more Stuff Blowing Up; Support, between healing and other supporting tasks (smoke grenades, cover fire); and MEC Trooper, between front-line offense or supportive tankiness. Additionally, there are psionic powers, which only a few soldiers can acquire, and more powerful psionic abilities are unlocked by using the more basic ones.
- The Dating Sim Shira Oka Second Chances includes a hybrid skill score/perk system as part of its Character Customization: you gain experience points during the game for succeeding at certain tasks or selecting certain choices and can use them to upgrade your stat scores or "quirks". Upgrading your stats (Intelligence, Fitness, Creativity, and Charm) enables you to build them up faster and get better grades, whereas upgrading your quirks follows a 3-tier system (you start out with universally negative quirks — Lazy, Jinxed, Scatterbrained, Amnesiac — that only hinder you and can upgrade them twice to actually positive ones) and gives you additional dialogue options and in-game benefits (e.g. upgrading Lazy to Determined decreases the probability of you showing up late to dates). Finding a balance between upgrading stats to keep your grades high enough and quirks to give you more XP opportunities is essential to getting through the game with a minimum number of Groundhog Day Loops.
Examples from other media:
- Many non-RPG-Mechanics Verse mangas provide various skill rankings in the supplemental materials, such as:
- Claymore Databook offers rankings for most main characters from the series in following stats/skills: Yoki, Agility, Muscular Strength, Spirit, Perception, and Leadership. These are ranked E through A (plus S for extremely overpowered individuals like Teresa), though Clare is the only character who made notable improvements in them during the Time Skip. There are even kind of "perks", coming in form of special attacks like the Windcutter or an ability to heal other Claymores.
- Attack on Titan Guidebook gives each main character a ranking on a 1 to 10 scale in following skills: Battle Skill, Initiative, Strategy, Teamwork, plus a unique "skill" that usually ranks 10 out of 10 and reflects their personal quirk, ranging from Eren's Passion to Christa's "Heavenliness".
- In Cactus Canyon, having a higher Rank increase the player's scores during the Quick Draw and High Noon modes.
- Instead of leveling up, players in Roll To Dodge: Savral gain unique skills or perks after enduring for a variable number of turns or dying. Unlike other examples, the players have no say in what these skills or perks are, since the game master doles them out based on how the player performs.
- GURPS is a classic example. Character traits fall fundamentally into four distinct groups: attributes (the four base stats), skills (based on said attributes and then improved individually), advantages (perks) and disadvantages (essentially 'anti-perks', handicaps to saddle one's character with for more character depth and bonus points...okay, primarily the bonus points).
- Dungeons & Dragons was late to this particular party for once. The now-familiar skills-and-feats scheme was introduced only with the game's third edition; before then, support for skills for non-thief characters was noticeably delegated to optional rules or even altogether absent, and "perks" existed almost solely in the form of racial and class abilities that might get unlocked with advancing level but generally didn't involve much choice. Moreover, both pre- and post-third edition these skills were and are handled more like perks themselves, with characters able to choose to have a given skill or not but little in the way of means to improve it further after that. The fifth edition made feats an optional mechanic that replaces generic stat increases and reduced their selection, while giving each feat additional properties, so they are no longer detached abilities or bonuses but entire expansion packs for the character.
- Both the Storyteller and the Storytelling System are based around "traits", which are basically a hybrid mash-up of stats ("attributes"), skill scores ("abilities" in oWoD, "skills" in nWoD), and upgradable perks ("advantages"). The latter include both storyline perks (like background) and active abilities (like the vampiric Disciplines). Attribute scores range from 1 to 5, abilities/skills and advantages from 0 to 5. Occasionally, levels up to 10 may be allowed. Trait levels are acquired by spending character points.
- The Serenity Role Playing Game has a nontraditional version of this. Skills and perks are purchased from a shared point pool at character creation and changeable at GM discretion (the RPG does not use a Class and Level System). There's a set of core skills that can be used with dice up to d6, then specialized into sub-skills that can use from d8 to d12+d2. Perks, called traits, are broken down into assets and complications and provide various bonuses and penalties.
- Ironclaw has skills and Gifts, adding skill marks increasing the size of the dice rolled. The biggest changes between editions included the consolidation of several skills and changing many specific skills to Gifts, as well as instituting flat costs of 4 XP per skill mark and 10 XP per Gift rather than varying costs, and making spells Gifts.
- Dragon Age features Focuses and Talents, which vaguely correspond to Feats and Skill Scores. Focuses represent a particular expertise in a narrower subset of certain Attribute checks (e.g. "Perception: Seeing") and give a flat +2 bonus to rolls where they apply. Talents have three levels, each of which gives the character a unique gameplay advantage. New Focuses can be learned at every new level (alternating between primary and secondary class Attributes), while Talents can be acquired or upgraded every other level.
- Apocalypse World and its many hacks use a unique variation of perks called "moves": apart from the "basic moves" available to all player characters (which describe which stat to roll for in specific situations and what the roll results mean), each additional move is character/playbook-specific and can range from switching out stats in basic moves (e.g. "roll for intelligence instead of charisma when trying to manipulate someone") to giving them entirely new abilities. The design is purposefully open-ended to allow seamless invention and integration of new moves into play.
- Lace & Steel has a large number of skill scores subdivided into Social, Courtly, Knowledge, Military, Movement/Perception, Crafting, and Magical categories (but no perks). To use a skill, you need at least level 0 (no modifier) in it, which you get for free in a handful of universal skills, plus in a number of skills associated with your social class (e.g. nobles get free Social and Courtly skills). You can buy additional skill levels (including level 0 in new skills) with Tech Points at character creation to increase the bonus to corresponding rolls, although non-class skill levels cost more than class ones, and higher levels cost more than lower levels. In-play, however, skill levels are gained via Stat Grinding: at the end of an adventure you roll for every skill you've used in its course to gain XP in it, increasing it by a level if you reach that level's cost (same as at character creation).
- Fate games have a variety of different ways to refer to its Skill Scores (most have Skills, but Fate Accelerated uses Approaches instead, while Jadepunk has Professions) and even a couple of different names for Perks (most use Stunts, but Jadepunk has an Asset system instead that modifies the Stunt basis), but most of them exhibit this. Some also have a third thing, Extras, used to build things like magic systems, super-powers, or giant robots.
- Planet Mercenary has 40 Skills, most which have Specialties that allow for rerolling one of the three dice when using a subset of the skill. Carbosilicate Amorphs get additional secret Specialties that unlock actual abilities.
- The cast page for Cucumber Quest gives Attack, Defense, and Spell scores for the characters, even though it's not an RPG-Mechanics Verse.
- Magience has an elaborate system of stats and special traits.
- In Not a Villain, characters in the Game have stats and Special Attacks.
- Grrl Power: Sydney's orbs apparently come with a skill tree. Fans quickly noted that the large number of nodes that have already been filled in imply that she's essentially working off someone else's save file.