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Message: <blockquote data-quote="Cheiromancer" data-source="post: 2274615" data-attributes="member: 141">Methods of Determining Experience (house rules + math)This thread indicates that the 3.5 method is the favorite method (~70%) of assigning xp.  Respondents prefer 3.5 because it allows lower level characters to catch up quickly with the rest of the group.  A distant second (~20%) is the 3.0 method, which divides xp equally among participants in an encounter.  Very few people (~1%) use a method like the one promoted in Grim Tales, which ensures that members of a party level at the same rate.  (Grim Tales doesn't ensure equal advancement if a character has a level adjustment- but Grim Tales handles LAs differently than I would.)Any of the methods requires recourse to charts and tables to assign xp.  What follows are some formulas that IMHO capture the essence of the various methods of calculating experience points.  They would be easy to write down in a spreadsheet, or with a calculator and paper.First, assume we are talking about a party encountering a group of monsters.X is a monster encounter composed of m monsters whose CR is x[sub]1[/sub], x[sub]2[/sub],... x[sub]m[/sub]. P is a party of n characters whose levels are p[sub]1[/sub], p[sub]2[/sub],... p[sub]n[/sub]This is what we want to calculate:xp(k) = character k's xp from encounter XTo do this a DM will have to calculate one or both of the following:Chi(X) = (x[sub]1[/sub][sup]2[/sup] + x[sub]2[/sub][sup]2[/sup] + x[sub]3[/sub][sup]2[/sup] + ... + x[sub]m[/sub][sup]2[/sup]) * 300 Rho(P) = (p[sub]1[/sub][sup]2[/sup] + p[sub]2[/sub][sup]2[/sup] + p[sub]3[/sub][sup]2[/sup] + ... + p[sub]n[/sub][sup]2[/sup])A 3.5-style xp formula (rapid catchup) isxp(k) = (Chi(X) / n) / p[sub]k[/sub]Chi(X) is divided by the number of characters, and then by character level.  Since low level characters divide by a smaller amount, they get more experience.A 3.0-style xp formula is the same, but uses the average party level instead of p[sub]k[/sub].  In other words, you divide Chi(X) by the total party level.  Everyone gets the same amount.A GT-style xp formula (equal advancement) isxp(k) = Chi(X) / Rho(P) * p[sub]k[/sub]Higher level characters get more xp, but they also need more xp to level up.  The result is that all characters level at the same rate.A fourth alternative exists, and that is to use a level independent experience system (LIES).  I suggest the following LIES:Each monster is worth CR[sup]2[/sup] * 100 xp, which is divided among the characters.In this system a character's level is calculated by dividing their experience point total by 100, and taking the cube root  (round fractions down).  Thus a character with 3000 xp is third level (rounded down from 3.10) and a character with 100 000 xp is exactly 10th level.If xp from LIES are divided equally, low level characters will level up much faster than high level characters.  Even if the xp is divided into as many shares as the party has levels, the low level characters will level up a little bit faster than the high level characters do.According to LIES, the expected treasure of a character is approximately (within a factor of 2) equal to that character's total xp.  If that is close enough, a DM can ensure that the experience that a party gains from an encounter will, on average, be equal to the treasure they earn.  1 gp = 1 xp, for a "1st edition feel."Incidentally, note that the XP costs for magic items and spells have to be adjusted to make the numbers work out; multiply by a factor of (0.3 * character level).  A 20th level wizard will have to pay 30 000 xp to cast a wish instead of 5000 xp, since she'll be earning about 6 times as much xp from encounters as a character in one of these other systems.</blockquote>

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