I know, I know. MTG is all about interactions with other players, but I'm only in high school and my friends are busy a lot. That's why I want to be able to play the best game ever even when I have nobody to play the game with. So I came up with a way to play by myself.
So, you want to use a commander deck or a deck with 100 cards or more. You start out with 30 life, and your opponent starts with 50. You play normally, but you have an opponent that isn't actually real. So you go first, play whatever you want. Then when your turn ends, it's your fake opponent's turn. You roll two dice and an effect happens in response to the number rolled.
12: Destroys all creatures you control.
11: Destroys all non creatures, non lands you control.
10: You discard 3 cards.
9: You lose 5 life.
8: Opponent gains 20 life.
7: Roll the dice 5 more times. If a 7 is rolled again from an extra roll, do not roll any more.
6: Opponent puts a 7/1 enchantment creature with haste onto the battlefield that attacks each turn if able.
5: Opponent puts a 1/10 artifact creature with defender and reach onto the battlefield that blocks the creature with the highest power and toughness you control. If two or more creatures are tied this way, it blocks all of them.
4: You put the top 20 cards of your library into your graveyard.
3: You sacrifice 3 non land permanents and one land. If it is Turn 4+, sacrifice 5 non land permanents and three lands.
2: Counters the next 3 spells you play.
Every time you roll, it counts as an opponent casting a spell. Effects that target an opponent or require an opponent to do something still targets the fake opponent, but you roll a die or dice to decide what happens.
There are many holes in this idea, but it should work with some decks. I created this for myself to play, so it works with everything in my deck. (As long as there isn't something big that I'm missing.)
Feedback would be appreciated