Each deck introduces five cards that won't be found in the expansion, but that will be considered connected to that block for Standard legality (meaning Planeswalker Decks will be playable in Standard). Here's what you can expect:

One copy of a mythic rare planeswalker Each Planeswalker Deck will have a brand-new planeswalker card, obviously of the Planeswalker the deck is themed around.

These cards are being designed to be fun and flavorful but not pushed for tournament play. The idea is we want new players to be excited by them and for them to have a big impact on the game, but we don't want established players to feel obligated to buy the Planeswalker Decks. As a default, the planeswalkers will be expensive to cast and splashy. There will be one copy of this card in the deck, with art tied to the appropriate world.

Two copies of a rare spell that has an effect and also tutors for the specific planeswalker.

It was important to us for the deck to have a planeswalker, but we wanted it to be mythic rare--which meant that each deck could only have one. Was there a way to help the planeswalker have a big impact if only one was in your deck? The rare was our solution to this problem. The rare usually will cost one mana less than the planeswalker (to help ramp into the planeswalker) and have an appropriately themed effect. It will then search your library or graveyard for a copy of the specific planeswalker and put it into your hand. (Note that it only looks for the Planeswalker Deck's version of the planeswalker and not any version. Allowing you to get any version had huge developmental issues.) This functionally allows the player to have three copies of their planeswalker, which will increase the chances that it makes its way into play. There will be two copies of this card in the deck and it will have art tied to the Planeswalker.

Three copies of an uncommon permanent that is enhanced by having the planeswalker on the battlefield.

For the uncommon, we are making a permanent that is upgraded if you have the relevant planeswalker on the battlefield. Note that unlike the rare spell, the uncommon is looking for any version of the planeswalker; not just the one that comes in the Planeswalker Deck. This card will be thematically tied to the Planeswalker of the deck in name and art. There will be three copies of this card in the deck.

Four copies of a common flavored to the Planeswalker.

At common, we have a basic staple effect--one the Planeswalker would cast most often, with art showing them casting it. There will be four copies of this card in the deck.

Four copies of an appropriate common dual land.

Oath of the Gatewatch and Shadows over Innistrad introduced a ten-card cycle of dual lands that enter the battlefield tapped. It is our intention to make sure that ten-card cycle stays Standard-legal so that budget players will always have access to them. For Planeswalker Decks, the plan is to include the appropriate ETB-tapped dual land that matches the colors of the deck. The card will have brand-new art tied to the world of the block. There will be four copies of this card. That means of the 60-card Planeswalker Deck, there will be four mechanically unique cards with ten total copies in the deck (one of the mythic rare, two of the rare, three of the uncommon, and four of the common). There will be fourteen cards with new art (the ten listed above plus the four copies of the dual land). All the rest of the cards will be from the large set if the Planeswalker Deck is tied to the large set and from the whole block if the Planeswalker Deck is tied to the small set. The art on all those cards will match the art used in the block.

The Planeswalker Decks will premiere with Kaladesh, this year's fall set, where they will replace Intro Packs.

Planeswalker (1)
1 Nissa, Nature's Artisan

Creature (27)
2 Thriving Turtle
2 Longtusk Cub
1 Sage of Shaila's Claim
2 Servant of the Conduit
4 Terrain Elemental
2 Thriving Rhino
2 Janjeet Sentry
2 Empyreal Voyager
3 Guardian of the Great Conduit
1 Bristling Hydra
2 Long-Finned Skywhale
2 Arborback Stomper
1 Riparian Tiger
1 Aethersquall Ancient

Sorcery (5)
3 Attune with Aether
2 Verdant Crescendo

Instant (2)
2 Appetite for the Unnatural

Enchantment (2)
2 Malfunction

Land (23)
4 Woodland Stream
11 Forest
8 Island