This article is going to have a rather unusual goal: being simple enough to teach not-quite-beginners how exactly priority and the stack work, while showing advanced technical players some aspects to the turn structure they might not have considered.
Before going any further, let's go over what "The Stack" and what "Priority" are. If you already know what these are in concrete and technical terms, feel free to skim ahead.
Imagine you're going to play the following game, called "A Stack of Priority Scribbles."
You and another person sit, each holding a notepad and pencil. You, being special, get control first - "control" being a prized chance at scribbling something on a piece of paper and putting it on the top of a pile between you. If you decline to put a piece of paper there, your opponent gets control and can put one there themself.
Now, whenever someone adds a piece of paper to the pile (it doesn't matter who adds it) control goes right back to you, and you can choose to add a piece of your own. Yes, this means that you can add twenty sheets in a row without the opponent being able to do a thing about it, because you get control back each time someone adds a sheet. You also get control whenever a piece of paper is removed. Aren't you special?
So, how are pages removed from the pile? If neither one of you wants to add an artistic scribble on paper to the pile, then the top sheet is taken off for everyone to admire. If there isn't any paper left in the pile when both of you pass, the game ends.
Games of "A Stack of Priority Scribbles"
can be really long, with both people adding a large number of papers to the pile in complicated patterns. Or it can be as short as both players simply saying, "I don't want to add a sheet in the first place."
... Okay, understand this game? Picturing it in your head? It's exactly
how the Stack and Priority work. Adding sheets with scribbles on them is the same thing as playing spells or abilities. Pulling them off the stack of papers is when they resolve. And who has "control" is how priority works in magic.
Take the following half-and-half example of the game being played. Allie is facing off against Bob, and Allie is the special one that gets to always go first.
Allie has control. She draws a picture of a Quirion Dryad
--- Allie gets control back immediately, but she shakes her head no.
--- Bob gets control, and draws something he dubs "Think Twice
." It goes atop the pile.
------- Allie gets control back and sketches a bit of lightning, names it "Shock
," which she puts on top.
----------- Allie gets control immediately back, but doesn't scribble on a sheet of paper.
----------- Bob gets control, and doesn't scribble anything either
------- Since neither scribbled anything, the top sheet of the pile comes off.
------- Both players admire the "Shock" piece of art.
------- Allie gets control again, but doesn't draw anything on her paper
------- Bob gets control, and passes as well.
--- Since neither scribbled anything, the top sheet of the pile comes off.
--- Another masterpiece to admire: Think Twice
--- Allie gets control again, and once again she declines to add a sheet of paper
--- Bob gets control and also opts to do nothingOnce again, due to both passing control, the last sheet - of paper comes off the pile.Both players appreciate the work of artistry that is "Quirion Dryad."
Allie gets control, and does nothing
Bob gets control, and does nothingSince neither player did anything, and there was no paper between them, the game ends.