Michael Dorn had virtually a blank slate when he took on the role of the Klingon Worf in Star Trek: The Next Generation.
In fact, in an interview with CNET, Dorn revealed that Gene Roddenberry told him to make the character his own. So he chose to make Worf be aloof from the other characters, essentially making the Klingon an outcast as he thought it would make sense that it would be difficult for a Klingon to be accepted aboard the Enterprise.
But while Dorn chose to make his character so different from the others, one thing he didn’t choose was the evolving door of aliens who always got the upper hand whenever fighting Worf. Dorn believed that losing so much would lead the audience to believe that Worf wasn’t a capable warrior. (He did get tossed around a lot in the earlier episodes of the series!) When Dorn protested, Roddenberry reassured him, telling him the scenes weren’t meant to make him look weak but the aliens look strong. But Dorn continued to object so a compromise was reached.
Michael Dorn was the reason the bat’leth was invented.
To make Worf appear more warrior-like and harder to defeat, he was given sword-like weapons to be used for battle. He worked with Dan Curry, the visual effects producer, to create the bat’leth, which became the traditional “sword of honor” used by Klingons.
In addition, Curry and Dorn worked together to create a form of Klingon martial arts that worked with the weapon, and episodes further into The Next Generation proved Worf to be a formidable opponent who used the bat’leth adeptly and without hesitation. Needless to say, no one doubted Worf’s abilities as a warrior after that, especially those who met him in battle.