The formal method for calculating the experience award for a character has changed in many ways over the versions. But it still remains one of the most contentious issues as each GM is required to moderate the results and players generally argue that more experience is required. This article lists all the prescribed methods in one place.
Basic D&D
Sum up the Gold Piece value of the treasure taken the add 100* Hit dice of the monster then divide by the Characters Level
AD&D
- Calculate the Gold piece value of treasure taken. Each GP taken adds 1 exp to the total Experience award
- For each monster Add its BXPV to the HP*(XP/HP) add the SA*SAXPB and the EA*EAXPV to the total experience Award (These values are derived from a Table)
- Divide the total Experience award equally between players
AD&D 2e
- For each creature calculate the Hit Dice or Level of the Creature
- Add the additional Hit Dice or levels from the Hit Dice Value Modifier table
- Multiply by the number of Creatures of that type
- Divide by the number of the characters
D&D 3.0
3.0 and 3.5 used the same experience calculation
D&D 3.5
- Find each characters Level accounting for monster characters ECL
- Find the CR for each monster defeated
- Lookup the XP award for a single monster in a table like:
** Note this table is an approximation not the exact values
4. Divide by this number of Characters in the encounter
5. Add up this EXP awards for all the monsters defeated by each character
D&D 4e
Each Monster description has an experience point value
- Total the experience points for all the monsters in an encounter
- Divide by the number of characters
D&D 5e
Each Monster description has an experience point value
- Total the experience points for all the monsters in an encounter
- Divide by the number of characters