Scale of the MapMagic Number 7 from back in '07). Indeed, as you can see below, the maximum (full health) movement for a man in Outdoor Survival is 6 hexes.
But the wilderness rules of D&D Vol-3, which use the Outdoor Survival map, also need to handle travel modes such as horses, ships, and even flying dragons (much faster than walking). There, Gygax made the hexes about twice as big (5 miles; compare to 6 miles in later material like Moldvay/Cook, i.e., 2 leagues), thereby cutting the hexes walked by about half, prolonging the adventure and handling horses without leaving the entire map behind them in a single day. I constantly engage in a never-ending debate with myself over the descriptive elegance of having 1 hex = 1 league, versus the need to have a larger hex size so movement in hexes is a manageably low number.
Life Level Chart
Each player gets one of these yellow cards to track their current life level. Each day without food or water decreases the respective track by one box; after several are missed, life level is decreased. This happens more quickly for water than food; and in the later stages the loss becomes exponentially greater. Life levels A-O (15 stages) are noted, starting with A (full health). The intimate connection between health and mobility is the key mechanic of this game; as soon as a single life level "point" is lost, movement is reduced from 6 to 5 hexes/turn. The longer you go without food or water, the worse your mobility is, and it becomes increasingly hard to get to the next food/water supply point. If prolonged, it quickly falls into a "death spiral" where reaching food/water becomes impossible. Indeed, even by life level L, movement becomes zero, and you are effectively dead at that point.
It's an elegant rule, and it does a reasonably good job of communicating the critical concerns of real outdoor survival (I like this game a lot). Tracking the connection for one person per player is fairly easy by using these cards. But in D&D, we are likely to be running many people, characters, mounts, henchmen, etc. (to say nothing of the DM with dozens or hundreds of monsters!), and trying to use this exact same mechanic would become quickly, totally unworkable. In D&D, of course, decreasing mobility from injuries was never part of the core rules -- but is referenced in the earliest edition as something a DM could consider ("Whether sustaining accumulative hits will otherwise affect a character is left to the discretion of the referee.", Vol-1, p. 18).
More to come.