Experience, often referred to as experience points or XP, is a game mechanic in Dungeons & Dragons.
Dungeons & Dragons is generally credited as originating the concept of experience points, which has since become a mechanic in video games of many sorts.
In all editions of Dungeons & Dragons, defeating opponents in D&D grants experience points. A character who accumulates enough experience points raises their character level, allowing them to become more powerful and obtain new abilities.
In certain editions of D&D, experience can be gained for other activities, which may include finding treasure, surviving or bypassing traps, or crafting magic items. They may be lost or expended, such as by level loss, crafting magic items, or casting certain powerful spells. Variant rules allow for level progression without experience points.
The notion of cumulative experience can trace its roots to the wargames which ultimately inspired Dungeons & Dragons. Various wargame rules of the 1960s incorporated some kind of "veteran" warrior status which could be attained. In Leonard Patt's 1970 wargame "Rules for Middle Earth" (Courier Vol. 2 No.7), "hero" characters exist with superhuman combat ability. Gary Gygax's Chainmail (1971) similarly had "hero" and "super-hero" characters.
When Dave Arneson created his Chainmail-inspired Blackmoor campaign, he incorporated a new mechanic allowing Men to be promoted Heroes, or Heroes to Superheroes. In Origins of the Game, Dragon #7 (Jun 1977), Gygax describes this as his inspiration for experience points in D&D:
- "Dave had taken the man-to-man and fantasy rules and modified them for his campaign. Players began as Heroes or Wizards. With sufficient success they could become Superheroes. In a similar fashion, Wizards could become more powerful. [...]"
- "The idea of measured progression (experience points) and the addition of games taking place in a dungeon maze struck me as being very desirable."
A detailed analysis of the origin of experince points apears in Playing at the World, chapter 184.108.40.206, "Levels and Experience".
The original Dungeons & Dragons 3-Volume Set, Men & Magic (1974), p.18, introduces the concept of experience:
- "As characters meet monsters in mortal combat and defeat them, and when they obtain various forms of treasure (money, gems, jewelry, magical items, etc.), they gain "experience." This adds to their experience point total, gradually moving them upwards through the levels."
Characters gain experience based on the amount of treasure they find, in addition to D&D. For example, defeating a troll grants 700 XP, while finding 7,000 gold pieces would grant 7,000 XP. Experience is reduced based on the dungeon level relative to the player's character level, with the assumption that more powerful creatures appear in deeper dungeon levels.
Different character classes need different amounts of experience to level up. Characters with high ability scores in their class prime requisite gain a percentage of bonus experience.
AD&D 1st edition
XP is now awarded only when a character returns to base. In addition to XP for killing monsters or acquiring treasure, the DM may give XP for capturing enemies for ransom, overcoming enemies by trickery, solving puzzles, or overcoming traps, as appropriate. Characters can optionally gain XP if they died and are restored to life.
XP is shared equally among those player characters who survive the battle. Characters who accumulate enough experience points to level up are additionally expected to undertake training, costing time and gold, before they can level up. Characters who behaved inappropriately to their character class or alignment, according to the DM's judgement, must spend more time and money in training.
The rulebooks note that many players found the idea of gaining experience by finding gold to be unrealistic, but defends their inclusion.
AD&D 2nd edition
Experience in Advanced Dungeons & Dragons 2nd edition is described in Chapter 8 of the Player's Handbook (2e) (1989), p.88, and Chapter 8 of the Dungeon Master Guide (2e) (1989), p.46-49, where it operates similarly to 1st edition, with some changes.
Much leeway is given to DMs to give ad-hoc experience awards, including for making the game more fun, for surviving, for the player getting better at D&D, and for achieving story goals. Groups may gain XP any time they overcome a significant risk, including defeating enemies without killing them. Players may optionally also gain bonus individual XP rewards, and slain characters may optionally be given XP for actions taken before they died. Experience values are given for individual magic items.
XP for gold is relegated to an optional rule. Training is now an optional rule. An optional rule requires demihumans (e.g. dwarves and elves) to require double, triple, or quadruple XP to level up.
According to Dungeon Master Guide (2e) (1989), p.29, changing alignment hinders a character's ability to gain experience (unlike 1st edition, where it penalized a character by one level). Characters who voluntarily change alignment must gain double the number of experience points to level up, while charactesr who change alignment involuntarily can gain no experience.
D&D 3rd edition
D&D third edition (2000) made many significant rules changes, including to experience.
All character classes now require the same amount of experience to reach a new level. As per Player's Handbook (3.0) (2000), p.144-145 and Dungeon Master's Guide (3.0) (2000), p.165-169 (and the same in the D&D 3.5 revision), XP is awarded at the end of an adventure, but cannot gain enough XP to gain more than two character levels in one adventure. It is presumed that they spend a certain amount of downtime in training and practice.
Traps give XP if the player characters surive, disable, or avoid it. Characters who die in an encounter still gain XP when they are returned to life. Notably, summoned creatures to not grant experience; e.g. if an enemy spellcaster uses a summon monster I spell.
Optional rules give XP for story events, accomplishing missions, roleplaying, and non-combat encounters. The DM may adjust the rate of XP gain, perhaps to allow slower progression familiar to players of older editions of D&D.
Crafting a magic item now costs experience points.
XP is no longer given for finding gold or treasure. This would set a standard going forward to future editions of D&D.
D&D 4th edition
As per Dungeon Master's Guide (4e) (2008), p.120-123, XP is awarded for overcoming encounters, including non-combat encounters such as skill challenges.
Traps or terrain hazards may give XP if they are part of a combat encounter, even if they are not defeated, but traps encountered moving along corridors do not grant XP.
Optional rules include varying the rate of XP (suggesting double XP progression to make it feasible to go from level 1-30 in thirty-five sessions), simplified progression which allows level-up every ten encounters or so, levelling up immediately upon gaining XP or waiting until the end of the session, giving XP to missing players to keep all players on the same XP total, and a table of quest XP rewards.
D&D 5rd edition
Dungeons & Dragons 5th edition's experience rules are detailed in Dungeon Master's Guide (5e) (2014), p.260-261. They are similar to the rules of D&D 3rd and 4th edition.
Experience level 2 and 3 are reached more quickly than in earlier editions, requiring only 300 and 900 XP, respectively. The rules suggest that a group may reach level 2 after a single four-hour session.
Traps no longer grant experience, although creatures summoned by your opponents do. Optional rules allow XP to be given for non-combat encounters. Optional XP awarding methods include story-based level advancement, session-based advancement, and XP awards based on adventure milestones.
- Playing at the World, chapter 220.127.116.11, "Levels and Experience".
- A Precursor to the Chainmail Fantasy Supplement (Jan 20, 2016). Playing at the World.