The time of Ceasar's assassination at the hands of numerous members of the Roman senate in 44 B.C. There were believed to have been 23 stab wounds. That is not an assassination, but a piss poor job of butchery. The conspiracy may have included over 60 people. That means they had lousy THACOs.
The Assassin in D&D has been a character class on and off again through the various editions going all the way back to OD&D. It was left out of the Moldvay basic set, and was included in Advanced D&D 1st edition.
Personally it never made much sense to me as a character class in a dungeon crawl setting. Instead it seems much more at home in urban adventures with plenty of criminal and political intrigues.
To the left is Lassiviren the Dark from the Rogues Gallery - played by Al Hammock.
If you're planning to play an assassin in a D&D game do some homework. Learn about the many subtle ways a target can be killed. There are many beyond the brute force acts that require face-to-face bladework. Try to find creative ways to limit risk to your character while increasing the threat to the target NPC.
Perhaps you decide to have your PC become a member of the target's kitchen staff or the staff at a favorite eatery of the soon to be deceased. If so don't go for something quick and obvious, instead make use of natural ingredients that take time before the poisoning takes effect. All the better to avoid suspicion and have days to prepare or make your quiet escape. For example, the Deathcap mushroom. "Would his majesty like a nice garden salad?"
Of course if your character's getaway is very clean and all suspicion is pointed in other directions how is one to become infamous? If notoriety and infamy are your goals then the more dramatic the attack the better.
"I needed that like I needed a hole in the head!"