During the rampup to the next edition of D&D, I figure it would be useful to look at how D&D changed over the different editions. Today I look at the origins of levels and what they meant.
Levels started with the Chainmail Miniature Wargame. First off you have to remember that in Chainmail for the ordinary fighting man 1 hit = 1 kill. In the fantasy supplement to Chainmail there was the Hero and the Super Hero. A Hero was worth four fighting men, and took four hit to kill. The Super Hero was worth eight fighting men, and took eight hit to kill.
When Gygax developed D&D he changed the 1 hit to a 1d6 roll. Likewise for the number of hits a character could take he changed that to 1d6 roll and called them hit points. The three original classes varied in modifiers to the 1d6 roll with Magic-users being the worst, and Fighters the best.
In general a level in OD&D could be looked at as a multiplier. A 4th level character was four times as effective as a first level character, and a 8th level character was 8 times as effective.