Balder was so well loved that the gods convenced everything in the world not to harm him. every tree, rock, or plant, spears, swords, Giants, men, etc. Loki hid a holly(?) plant from them, though, so it was the only thing that could still hurt him.
once they werwe convinced Balder couldn't be hurt, the gods amused themselved by throwing stuff at him and watching it bounce harmlessly away. (they don't have to be creative. they're gods.) since Hoda was blind, he couldn't play. then Loki pretended to help Hoda by giving him a holly branch and helping him aim. Baldur was hit, and died, and went to Hel, which was run by Loki's daughter (named hel). baldur stays dead until the world ends, after which hell is killed and he gets to leave.