From Compsci.ca Wiki
Minsc is a fictional character from the Baldur's Gate series of D&D RPG's. You find him in Nashkel, where he asks you to help him rescue Dynaheir from the Gnoll Stronghold. Minsc has issues with Edwin, who very much wishes to kill Dynaheir.
Minsc is mentally unstable. He has suffered from numerous headwounds. This may explain, to some extent, his berserker attitude, best illustrated when he says, "I will inspire you by charging BLINDLY ON!"
Minsc enjoys kicking evil's butt. He is extremely good aligned, as evidenced by such quotes as, "Jump on my sword while you can evil. I won't be as gentle!" and "Evil meet my sword; SWORD MEET EVIL!"
One of the most interesting aspects of Minsc is his companion, Boo. Boo is a Minature Giant Space Hamster, although some believe Minsc is just crazy and that Boo is in fact just an ordinary hamster. Minsc and Boo are Minsc and Boo, and they shall not be seperated, not even when the protaganist and his companions (including Minsc) are taken prisoner.
Minsc also has a special connection to Lilacor, an evil, talking sword. Lilacor oftens suggests to kill rich people and take the money. It is strange that Minsc takes to Lilacor, despite their obvious alignment conflicts.
Surprisingly, Minsc is a ranger. It was often thought that Minsc should have been a fighter in Baldur's Gate I, and when Baldur's Gate II introduced kits (subclasses), it made sense that Minsc should be a berserker fighter. But he was not. Minsc was Minsc, the ranger, protector of Dynaheir/other witches after Dynaheir's death, such as Aerie.