In defense of coin-weight encumbrance
The OD&D method of using coins as a unit of measurement for encumbrance is not intuitive for players. A player has reasonable references for what 10 pounds feels like—like a 12-pack of soda cans—but the weight of 50 or 100 coins is less familiar. But D&D is all about choices. A henchman died while finding the treasure? You really should return his body for proper burial. But the body weighs 1750 coins—1750 coins you could otherwise carry out of the dungeon. That plate mail doesn’t just slow your movement, it’s 750 coins you won’t bring out of the dungeon. (It looks like an OD&D coin conveniently weights about a tenth of a pound—four times the weight of a U.S. half-dollar coin.)