If you need a refresher, after Ned Stark gets executed, Tywin got Tobho Mott to melt down Ice into two swords. He gave one to Jamie called Oathkeep while the other one gave to Joffrey call Widow’s Wail (he was really a piece of shit). Joffrey uses that sword to cut the pies during the purple wedding and stuff.
Reading in my ttrpg? Impossible. All that matters is the dm regurgitating the rules for the players.