Gentlegamer
Adventurer
I would say the truly fundamental difference between the original D&D game and any of its later incarnations is that the original game was actually incomplete and required rules knowledge from the Chainmail game to play.
howandwhy99 said:OD&D had no player rulebooks. The rules were for the referee to run the game.
If you are a player purchasing the DUNGEONS and DRAGONS rules in order to improve your situation in an existing campaign, you will find that there is a great advantage in knowing what is herein. If your referee has made changes in the rules and/or tables, simply note them in pencil (for who knows when some flux of the cosmos will make things shift once again!), and keep the rules nearby as you play. A quick check of some rule or table may bring hidden treasure or save your game "life".
Rolling the dice well is not a tactic. Dice rolls are rules in action, and as such they come under the purview of the referee. The player has no ability to change the result of the dice except through interacting in the play world before the roll is made. In fact, he has absolutely no need to roll the dice at all. The referee could roll every die behind the screen every time. The drawback to this method, however, is the players are not able to learn the difficulty of their attempted actions from the roll results as well as from the descriptive results. The players' true skill comes not from lucky dice rolls, but from choosing when and when not to roll them. These decisions are best made by thinking in character.
Keeping rules behind the curtain/shield is necessary to stop the game from becoming a matter of number crunching for the players as the numbers are the odds for their attempted actions. Learning the degree of difficulty comes through role-play with each particular referee. If the players are in charge of the rules, it removes the necessity of role-play and instead promotes rule referencing, rule-speak, and rule-think.