XP Guidelines for Old-school D&D
Here’s a guideline I've been working on for XP to be awarded per session in 1st edition AD&D. Before we continue, please note that this guideline is not a milestone system by another name. Rather, I've introduced it into my own Greyhawk campaign in order to provide: (1) a baseline against which I can check whether the XP actually being awarded in an adventure, in accordance with the DMG, is commensurate with the challenges being faced and the desired rate of advancement; and/or (2) a recommended XP to be awarded per session to ensure a graduated rate of advancement based on the average party level. Here, average party level is worked out by adding the levels of all party members; e.g., a party of seven characters, consisting of three level 5s, two level 6s, one level 7 and one level 8 would have an average level of 6 ((5+5+5+6+6+7+8=42)/7= average level of 6). As a rule of thumb, I'd treat multi-classed characters as being one level higher than their highest level....