Hmm. I think this machine might be acting up.
As usual, you'll be able to find the Comprehensive Rules here on our website, and Oracle text updated in Gatherer—at this time, one or both of those might not be updated just yet, so I'm describing a general truth here. Keep in mind that this article was written before the rules changes were finalized in editing, so there may be minor deviations from what I describe below.
Read on and find out!
Modern Horizons had a handful of rules changes, but the bulk of the matter here is with Core Set 2020, including two new templates! Well, one isn't new, but it just got widespread adoption.
Welcome back for another Update Bulletin! I've fired up my Silver Sliver brand time machine (patent pending) to visit the old Tolarian Academy, circa the year 3300 AR (that's Argivian Reckoning, for those new to the school). I haven't seen Teferi around yet, but he'll be here any time now if he's not already enrolled.