Days of High AdventureGamers on Their Own: The Challenges of Early D&DDays of High Adventure - RSS 2.0
And of course, there were simply holes in the rules and the occasional error or typo that made things more difficult. It's not easy to see many of the holes today, because our RPG-saturated brains automatically fill in what's missing. But back then just trying to understand what a "hit point" was could be difficult and the poorly described (or downright absent) rules for surprise and combat round order made playing the game a real challenge. The designers assumed a background in miniatures games, but if you weren't fortunate enough to possess such experience, even simple concepts like time, movement, and distance in the game were confusing.
But D&D players of the time were more than up for the challenge. The lack of concrete answers led many to develop their own rulings, some of which were codified into notebooks filled with house-rules. Frequently, decisions were made by group consensus, ensuring that everyone was more or less satisfied. So-called "rules lawyers" were a phenomenon of later versions of the game, but there weren't enough rules to lawyer in those early days. Instead, players often got traction by simply making a good case. Debating skills and persuasive speaking helped convince the referee and the other players that whatever the player was attempting at the time would (or at least might) actually work. Bags of flour to find the invisible foe, kamikaze mules laden with barrels of lamp oil and a long fuse, and trap-finding rats on long leashes were just some of the creative strategies players developed.
Groups found that not every ruling by the referee or every developed house rule was a good one. Trial and error was the only method they had at their disposal, but learning what didn't work was sometimes more valuable than what did, because they discovered a true understanding of the game. A poor decision now could create a bad precedent in the future. Things that worked for the characters could work for the monsters, and vice versa. All old hat to GMs today, but these were new concepts then.
And sometimes, players and referees trying to understand and enforce the rules that were provided simply made mistakes. For instance, throughout the booklet, monsters are assigned a stat labeled "% in Liar." This is meant to be the chance that the monster is encountered in or near its lair, but the word is misspelled. Many referees took the "% in Liar" stat at face value and decided that it meant that such was the chance that the monster, if spoken to, would tell a lie. One such referee even applied it to the non-human henchmen following the PCs. A player would ask his followers if they had enough rations with them before mounting a long wilderness expedition. The referee would secretly roll dice and then answer for them. Sure enough, a few weeks later, the player would discover some of his henchmen dead of starvation.