1. Take the character’s old experience point total and subtract the minimum number of XP needed to reach the character’s level on the old table. For example, Sigretta is a 7th-level fighter created under the 2nd Edition AD&D rules; she has 87,500 XP. The minimum XP Sigretta needed to reach 7th level was 64,000 XP. 87,500 – 64,000 = 23,500.
2. Subtract the minimum number of XP needed to reach the character’s level on the old table from the minimum needed to reach the next level. For example, Sigretta would have needed 64,000 XP to reach 7th level, and she would have needed 125,000 XP to reach 8th level. 125,000 – 64,000 = 61,000.
3. Divide the number you got in step 1 by the number you got in step 2. In Sigretta’s case, 23,500 ÷ 61,000 = about .385.
4. Subtract the minimum number of XP needed to reach the character’s level on the new D&D table from the minimum needed to reach the next level. For example, Sigretta would have needed 21,000 XP to reach 7th level and needs 28,000 XP to reach 8th level. 28,000 – 21,000 = 7,000.
5. Multiply the number you got in step 3 by the number you got in step 4 and round down to the nearest whole
number. In Sigretta’s case, .385 × 7,000 = 2,695.
6. Add the number you got in step 5 to the minimum number of XP needed to reach the character’s level on the new XP table. This is the character’s adjusted experience total. In Sigretta’s case, 2,695 + 21,000 = 23,695.