I'm making a sentient magical weapon for my players to stumble across. I wanted to give it a few properties that would make it more evil, as it is a cursed weapon found within a necromancer's dungeon. I was reading the Minor Properties that I can give to a magical weapon and concluded that Wicked (DMG p. 143) was the best choice as it would influence players to act strangely, more evil, and selfish than their alignment would suggest.
Now that I have done that, I'm wondering how it works.
Do the characters need to make any saving throws against the weapon's influence, or, should I just role play it out and say they “have a strange urge to do the wrong thing”?