For questions about the Frontier format, an unofficial format which permits all cards since M15 that have been in a Standard-legal set. Its identifying time cutoff is the new M15 card frame.
Frontier (also known as Postmodern or Contemporary) was created in 2016 in Japan, due to the popularity of Modern, but the cost and the difficulty in finding some of the older cards in the format, a few stores in the country decided to use the change to card borders from M15 (black bottoms with rounded corners of the background, and a foil mark at the bottom middle of rares) as a new starting point.
Aside from the different starting point, this format follows all deck construction rules of all other common eternal formats, like mtg-modern:
- 60 card minimum deck with no maximum, so long as the player is able to shuffle the deck without assistance.
- a 15 card maximum sideboard.
- a player's combined deck and sideboard may contain any number of basic land cards and no more than four of any card with a particular English name other than basic land cards, and cards that specifically state they ignore this rule.
Any card that has appeared in a set printed with the M15 border is legal, not only copies from those sets, as determined by the English name. Masterpiece cards, though opened in packs of these sets, are not a part of the set, and not legal unless regular versions of the card were also in a legal set.