In earlier versions of Dungeons & Dragons, a character with a high ability score in their class' prime requisite receives a bonus to all experience he earns. For example, the 1983 Frank Mentzer edition included this chart:

Prime Requisite Score Adjustment to Experience
3-5 -20%
6-8 -10%
9-12 No adjustment
13-15 +5%
16-18 +10%

What is the reason for this rule? Did the game's designers ever explain it, either officially or anecdotally?

  • 7
    \$\begingroup\$ Interestingly, prime requisite bonuses date all the way back to the original version of the game...the OD&D brown (and white) box rules. Page 11 of Volume One: Men & Magic lists "Bonuses and Penalties to Advancement due to Abilities". The adjustments appear to be very similar to those in the later 1983 Mentzer basic edition (the OD&D rules were first published in 1974). \$\endgroup\$
    – Badmike
    Commented May 13, 2012 at 21:35
  • \$\begingroup\$ If you want to know "what were they thinking" you'd need to ask Robert Kuntz as he seems to be the only one of the TSR originals still alive. Arneson, Kaye, and Gygax have all passed away. Tim Kask, Jim Ward, and Frank Mentzer may also have an insight due to how long they knew Gary G. \$\endgroup\$ Commented Sep 6, 2015 at 15:44
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    \$\begingroup\$ This question is being discussed on meta: Is this question about experience points in earlier versions of D&D off topic as a "rule intent" or "designer reasons" question? \$\endgroup\$ Commented May 4, 2021 at 18:41
  • 5
    \$\begingroup\$ I’m voting to close this question because it explicitly asks for design reasons, and [designer-reasons] questions are off-topic by community consensus. \$\endgroup\$
    – Oblivious Sage
    Commented May 5, 2021 at 13:17
  • 1
    \$\begingroup\$ I voted to leave open, as we discuss this question in meta. \$\endgroup\$
    – Akixkisu
    Commented May 5, 2021 at 15:03

4 Answers 4


When building characters, with "in order" statistic generation, or "assign existing roll" statistic generation, the XP bonus acts as an incentive to produce two outcomes. For "in order" character generation, it strongly suggests to players that they make their character "fit" their statistics, in particular by aligning their character selection with their highest statistic. No INT18 fighters please, we're Gygaxian. Correspondingly, with player assigned statistics (and points buy, obviously), it encourages characters whose statistics match their function in at least one statistic, their primary one. No STR18 WIS9 clerics please, we're Gygaxian.

Given that primary statistics also limit spells and levels; there is a strong rules based encouragement for character statistics to match assumed "rule ideal" types of characters.

Secondly, with statistic degrading poisons, traps, effects and magic; the loss of XP when your primary statistic is degraded below 9, is an encouragement for Fighters to regain their Strength, Clerics to regain their Wisdom, etc. Again, this encourages actual characters to match a rule ideal "type" of character at the level of statistics.

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    \$\begingroup\$ Actually, the Stat minimum for spells was not in the Mentzer editions. So, having a spellcaster with a low Prime Requisite was no hindrance to their career apart from XP earned. \$\endgroup\$
    – YogoZuno
    Commented May 14, 2012 at 8:14
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    \$\begingroup\$ @YogoZuno the stat min was introduced in Greyhawk (page 8) for Magic Users (INT for spell level) and Paladin (Charisma) ... checking ... and in Strat Review for the Ranger, and in Blackmoor for the Monk. \$\endgroup\$ Commented May 4, 2021 at 17:39

The bonuses in original D&D (OD&D) since the beginning, result in a way to encourage the player towards a specific character class. The three 'roles' were Fighting Man, Cleric, and Magic User.

Original D&D—the edition you reference was a modification/improvement of that—required you to roll three dice, in order, for your stats. Many players who wanted to work a fighter might end up with a 9 strength and a 17 wisdom, and they would just play the fighter despite having bonuses should they have played the cleric. It appears the prime requisite bonuses are there to reward a player for "taking a chance" on a character class he might not normally choose. The 5-10 percent added to experience (in contrast to the 10-20 percent LOST if the prime requisite was 8 or under) would be a substantial bonus in early editions of the game where EXP were sometimes scarce and character longevity was not guaranteed.

Here are the original Prime Requisite bonuses from the OD&D rules. It is interesting to note the changes from this to later editions:

In OD&D there are only three classes (roles): Fighting Men, Magic Users, Clerics.
All abilities are rolled by 3d6, in order.

  • STR is prime requisite for Fighting-Men.
  • INT is prime requisite for Magic Users.
  • WIS is the prime requisite for Clerics.

The section Bonuses and Penalties for Advancement Due to Abilities from Men and Magic, p. 11 says the following:

(Low score is under 8; Average is 9-12; High is over 13)

Prime Requisite 15 or more: Add 10% to earned Experience
Prime Requisite 13 or 14: Add 5% to earned Experience
Prime Requisite 7 or 8: Minus 10% from earned Experience
Prime Requisite 6 or less: Minus 20% from earned experience

There are ability bonuses given for high CON, DEX or CHR, but they are unrelated to Experience point awards.

Interestingly, besides the Experience point bonuses, there is little advantage to having a high STR, INT or WIS except for intangibles: A high STR is said to help in opening traps, A high INT will add languages and affect referees decisions about certain actions the player might make, A high WIS acts in the same way as a high INT (might affect decisions made per the referee's decision)

  • \$\begingroup\$ 'despite having bonuses should they have played the cleric' - Sorry, but apart from bonus XP, the only benefit of a high Wis was a bonus on Saves, and that applied to all classes, not just Clerics. \$\endgroup\$
    – YogoZuno
    Commented May 14, 2012 at 8:07
  • \$\begingroup\$ See comment below...you really have to go back and find out why they are given in the Original (OD&D) rules before you extrapolate reasons for later editions, because in many cases those later editions are merely aping stuff that came before. \$\endgroup\$
    – Badmike
    Commented May 14, 2012 at 16:39
  • 2
    \$\begingroup\$ @Badmike Answers aren't necessarily displayed in a predictable order, so 'below' isn't necessarily a useful descriptor. Could you perhaps mention the name of the poster? \$\endgroup\$
    – GMJoe
    Commented May 16, 2012 at 4:36
  • \$\begingroup\$ I added the citation from men and magic, and made a modest edit. \$\endgroup\$ Commented May 4, 2021 at 17:37

A primary reason was to carry over the pattern from Original D&D (1974) and the first issue of the cleaned up Basic D&D (Holmes 1977 and then Moldvay 1980). That bonus structure was in the original game. (See @Badmike's answer for details).

Mentzer's Basic/Expert/Companion/Master/Immortal Dungeons & Dragons (1983, aka BECMI) was a reorganization and improvement to the original game that was less complicated than Advanced Dungeons and Dragons (AD&D 1e) - the two were parallel product lines that replaced the 1974 original game (in different styles).

As a side note, the Holmes Basic D&D (1977) had in it a direct reference to Advanced Dungeons and Dragons as the "what you do next" once the characters got to the end of 3rd level - which is as far as that Basic Book went. It too had the same XP bonus structure. Moldvay/Cook Basic/Expert and BECM(I) decoupled from AD&D 1e. (A complete listing of D&D editions is here).

The rest of the answer is found in the AD&D 1e PHB

Original D&D, Holmes Basic, the Basic (B/X), the (BECMI) D&D edition that you cite, and AD&D 1e were all deeply interrelated. They are all built around the same OD&D chassis (that simply offered those bonuses without explaining why, see this answer by Badmike); the AD&D 1e PHB offers some of the why. Gary Gygax is that book's author; AD&D grew out of OD&D.

Here's the "why" for Strength.

Strength is the forte of fighters, for they must be physically powerful in order to wear armor and wield heavy weapons. Therefore, strength is the major characteristic (or prime requisite) of fighters, and those fighters with strength of 16 or more gain a bonus of 10% of earned experiencec(explained later). (PHB P. 9)

Here's the "why" for Intelligence.

Moreover, intelligence is the forte of magic-users, for they must be perspicacious in order to correctly understand magic and memorize spells. Therefore, intelligence is the major characteristic of magic-users, and those with intelligence of 16 or more gain a bonus of 10% of earned experience. (PHB P. 10.

The explanation for Wisdom, on the other hand, isn't as 'back portable' from AD&D 1e; that edition featured bonus spells for higher wisdom and lacks the clarity of the STR and INT "why" points. The pattern @Badmike noticed is consistent: encourage a player with a high prime requisite in a given score to choose a particular class. (That was by no means required).

Given the space restrictions and the 'rush' to publish OD&D, the "why" was never explained in the seminal volume: Men and Magic.
AD&D was the next edition published. In it, EGG expended a significant amount of text in explaining some things. (And more in the DMG, but he didn't explain everything).

By the time Basic was published, early 80's, this bonus had become axiomatic. Was the "why" necessary?
For those who cared, it had already been explained in the AD&D PHB a few years prior.
FWIW: if our once-active member ExTSR does drop by again, he can answer it with some clarity as the core author of that (BECMI) edition. (Not betting the rent money on that).

For further reading on both how and why Gygaxian design ideas - "Gygaxian Naturalism" is not the same as "realism" - strike so many contemporary players (and DMs, and game designers) as odd, Justin Alexander and James Maiszewski explain how deeply ingrained in OD&D, AD&D 1e, and BECMI that design philosophy ran.

  • \$\begingroup\$ Maybe provide or link to a definition of 'BECMI'; I've owned most of the editions you mention here, and I have no idea what that acronym means. \$\endgroup\$
    – Marq
    Commented May 5, 2021 at 10:32
  • \$\begingroup\$ @Marq I spelled it out and I provided a link to a QA answered by RSConley that summarizes all of the D&D editions. \$\endgroup\$ Commented May 5, 2021 at 12:04

I'm only guessing here, but for the majority of classes under those systems, you were required to have a high value in your prime requisite, but there was virtually no system bonus for those high values. Sure, Str, Dex and Con gave all characters in-game bonuses, but high Int gave you nothing but languages. So, to me, the extra XP was a way of giving those high stats an in-game bonus.

  • \$\begingroup\$ When you go back to Original D&D, ANY high ability in your prime requisite gave you a XP bump, while a low ability gave you a minus. This was a -20% to a +10% swing for some character that instead of playing a fighter with a 8 STR went with playing a cleric with a 15 WIS instead of vice-versa. Remember, most bonuses as we see them in the rules come from LATER editions, which piled up the benefits from high prime requisites...but their origins are from the first white box rules. So really you have to go back to the beginning and ask yourself why these bonuses were given in the OD&D rules. \$\endgroup\$
    – Badmike
    Commented May 14, 2012 at 16:38
  • \$\begingroup\$ I can't go back further than what I have - earliest rulebook I have is the first Mentzer edition. Thanks for clarifying. So, were there any other stat bonuses? To hit and damage for Str? \$\endgroup\$
    – YogoZuno
    Commented May 14, 2012 at 23:12
  • \$\begingroup\$ Yogo let me see if I have time to put up the "original" prime requisite bonus chart....it is very interesting in what was kept for later editions and what was left off. \$\endgroup\$
    – Badmike
    Commented May 15, 2012 at 17:54

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