Every distinct wording since 2010, newest first.
February 5, 2021 · Kaldheim
In a Planechase game, rolling the planar die is a special action. A player can take this action any time they have priority and the stack is empty during a main phase of their turn. Taking this action costs a player an amount of mana equal to the number of times they have previously taken this action on that turn. Note that this number won’t be equal to the number of times the player has rolled the planar die that turn if an effect has caused the player to roll the planar die that turn. See rule 901, “Planechase.”
June 1, 2020 · Companion Change
In a Conspiracy Draft game, turning a face-down conspiracy card in the command zone face up is a special action. A player can take this action any time they have priority. See rule 905.4a.