Demihuman Advancement in OD&D
by Scott MooreChapter 19 of the 1991 D&D Rules Cyclopedia gave an alternate 36 level progression for demihuman characters to use in campaigns where the normal maximum level limits on non-human characters are not enforced. Although more powerful characters can be created with these variant rules, the standard rules follow the level limit and Attack Rank progression system introduced in the earlier Companion and Masters boxed sets.
Although the Rules Cyclopedia does not allow for switching between the two progression systems, the following mechanic will allow demihuman characters to continue to gain character levels after attaining their maximum Attack Rank. This method is based on transitioning a character's Attack Rank to the same level of combat ability in the level-based progression system, and then following the regular level progression method from there. This results in a disproportionably large cost in XP to switch between the systems, but with a correspondingly large gain in hit points (and, for elves, magic ability) when initially transitioning between the systems.
For demihuman characters that followed the standard Attack Rank advancement, use the tables below to transition over to the level progressions detailed in chapter 19 of the Rules Cyclopedia.
Dwarf Attack Rank to Level Progression Transition
| Level/Attack Rank | XP | Gained hp | Combat Ability |
| 12/M | 2,600,000 | - | Attack Rank M (fighter 25-27) |
| 25 | 3,200,000 | +23 | Attack Rank M (fighter 25-27) |
| +1 | +200,000 | +2 | As a fighter of equal level |
Dwarves gain +2 hp per level past 26th. Their combat ability continues to progress as that of a fighter of equal level. The "Gained hp" at level 25 takes into account the transition of +3 to +2 hp/level beyond 9th level when switching between the two systems.
Elf Attack Rank to Level Progression Transition
| Level/Attack Rank | XP | Gained hp | Combat/Magic Ability |
| 10/M | 3,100,000 | - | Attack Rank M (cleric 29-32)/Elf 10 |
| 29 | 4,900,000 | +19 | Attack Rank M (cleric 29-32)/MU 29 |
| +1 | +200,000 | +1 | As a cleric/MU of equal level |
Elves gain +1 hp per level past 29th. Their combat ability continues to progress as that of a cleric of equal level. Spell casting ability progresses as per the magic user class.
Halfling Attack Rank to Level Progression Transition
| Level/Attack Rank | XP | Gained hp | Combat Ability |
| 8/K | 3,000,000 | - | Attack Rank K (cleric 29-32) |
| 29 | 5,200,000 | +1d6+20+CON bonus | Attack Rank K (cleric 29-32) |
| +1 | +200,000 | +1 | As a cleric of equal level |
Halflings gain +1 hp per level past 29th. Their combat ability continues to progress as that of a cleric of equal level.
General Skills
When switching to the level progression mechanic as detailed above, demihuman characters gain additional general skill slots based on their level, rather than their XP total. Dwarf characters gain one additional skill slot at each of levels 25, 29, and 33. Elf characters gain one additional skill slot at level 29 and another at level 33. Halfling characters gain four additional general skill slots at level 29 and one additional skill slot at level 33.
Immortality
Advancing a demihuman character through all Attack
Ranks and 36 character levels is a feat worthy of being a step on the path to
immortality. Such an accomplishment
fits nicely as a requirement for the Epic Hero, Paragon, or Polymath
paths.