Plot booster

A plot booster is a concept used in Legacy-style board games, being an unknown element added to a certain game and thereby changing certain rules that players are used to. 
==In Magic==
In connection to Magic: The Gathering, a plot booster named "Uncovered Cavern" was first mentioned on the test card <c>Planequake</c> in the Mystery Booster set. No such booster pack is part of that set in reality, much like Contraptions weren't part of Future Sight though they were mentioned on . 
It may be assumed that if the plot booster would be opened, its mysterious contents could be added to a game of Magic while it is in progress, changing the playing environment drastically. A plot booster can only be opened if certain circumstances are met.
==Example==
==Rulings==
* If you don't have the appropriate unopened plot booster when instructed to open one, that part of the spell or ability's effect is ignored. 
* Creatures and planeswalkers dealt lethal damage by Planequake won't be destroyed until state-based actions are performed, after you've opened the "Uncovered Cavern" plot booster if applicable.
==See also==
* Legacy (keyword)
==References==
Category:Booster products
Category:Miscellaneous mechanics