However, Gary Gygax was opposed to using critical hits and thus kept them out of the official rules. His vision of combat was much more cinematic, that is more like the fight between Robin Hood and the Sheriff of Nottingham in the 1938 classic Adventures of Robin Hood with Errol Flynn and Basil Rathbone respectively.
In 1989 with the publishing of the AD&D 2nd Edition Dungeon Master’s Guide, there is an optional rule for critical hits with two methods — double damage on a natural 20 or an additional attack on a natural 20. Note that this was an optional rule and Zeb Cook recommended against using it.
In Grymurld,™ I tried out the hit location rules from Blackmoor and soon the players and I came to dislike them quite a bit. It was too easy to kill monsters and characters with head shots (15% chance of a success hit going to the head which had 15% of the total hit points). Inspired by the AD&D Monster Manual Giant Lizard which would bite for double damage on a natural 20, I allowed both PCs and monsters to do the same.
The players loved it! In spite of the risk of being on the receiving end of a critical hit, the players enjoyed the chance of scoring a critical hit. Even though it was only a matter of luck to roll a 20, the players felt a keen sense of satisfaction when doing so. Did this violate the spirit if not the letter of Gygax & Arneson’s D&D? Who cares?!? If players and the GM alike enjoy the rule then by all means “damn the torpedoes, full speed ahead!”
And so I present to you, memorable critical hits:
Exploding Dice = Exploding Undead
Once upon a time there was a knyghte who tried to be a conventional paladin but just could not quite pull it off who was known as Syr Stephen d’Essexe. One of the many things that Syr Stephen was reputed for was always giving first strike to his opponents as well as never striking an opponent who was disadvantaged (stunned, prone, helpless, &c.). Now he could get away with this because the player rolled so well. Syr Stephen’s player rolled better than anyone I have ever seen in 30+ years of gaming. In the particular campaign that Syr Stephen was in, the rules I used for critical hits were borrowed from MERP (Middle Earth Role Playing) — upon rolling a natural 20, roll again. A result of 1–19 meant double damage while a natural 20 meant roll again. The third result would be triple damage or roll again and so on ad infinitum. Given Syr Stephen’s reputation, it was not surprising that he scored critical hits often and usually did triple damage (two natural 20s) with the occasional quadruple damage (three natural 20s).
One day Syr Stephen and his fellows encountered a powerful spectre (drain 2 life levels on a successful hit!). Syr Stephen was nervous but his sword was enchaunted versus the undead (more so v. incorporeal). I reminded the player that only the magical bonus of the weapon would damage the spectre and the not the physical part nor the strength or skill bonus. I think the sword was +12 versus incorporeal which meant that each hit would do 12 points of damage. At this point you are no doubt wondering why I give a combat with incorporeal undead as an example of critical hits when the rules clearly state that undead, especially incoporeal undead have no vital organs thus are immune to critical hits. In Grymwurld,™ I allow critical hits against the undead because it is fun! However, the undead in Grymwurld are stronger than standard D&D (AD&D was only a d8 whereas I used a d12). At any rate, as you might have guessed by now, Syr Stephen allowed the spectre to take a swing at him first. The spectre punched right through Syr Stephen’s shield and armour taking two energy levels away. The other players howled at Syr Stephen for being “chivalrous” but the good knyghte was not daunted. He responded by rolling a natural 20, followed by a natural 20, and then a third natural 20, and then a fourth natural 20, and then a fifth natural 20, and then… a 4. Still, five natural 20s in a row which gave him sextuple (6×) damage or 72 points of damage! The spectre had 52 hit points and went to -20 in one shot. All of us at the table were aghast (pun intended) at what Syr Stephen had wrought!