TL;DR: the short version: What is Chaos-Tower? Chaos-Tower is a casual out-of-the-box format best for 4 players. It's a single 400 cards, five-color deck shared by all the players. And there are some legacy elements. How to build the Chaos-Tower/What do you need? Build a singleton 400 cards deck. There should be around 140 lands in there. Feel free to use any cards you want to, but I recommend reading through the blog, there are some ideas for construction. Optional: Have some unopened packs with you. You should need like 2-4 packs per game played, some inner-sleeves and a marker. If you don't want to spend that money or have no packs with you, there should be a sideboard (maybe made out of random bulk). How to play Chaos-Tower?/The rules. Rule 1: There is only one deck and one graveyard. Cards referring to "your" deck or "your" graveyard now refer to "the" deck or "the" graveyard. Rule 2: There is one free mulligan. If your second h...