Four preconstructed theme decks have been released as part of the set. The theme decks are "Battalion" (White/Blue), "Going Rogue" (Blue/Black), "Shamanism" (White/Black/Green), and "Warrior's Code" (Red/Green). The block has a tribal theme, focusing heavily on creature subtypes, revolving around eight primary creature types. Each of these appear in two or more colors, with one as the primary color:  "Lorwyn" saw the release of an entirely new card type, the Planeswalker. This marks the first time that Wizards has added a new card type to the current game, as "" introduced all current card types, other than the type "Tribal". A single tribal card, , was printed as a future-shifted card in "Future Sight". Another significant creature type is the shapeshifter type, all of which have the ability "changeling." Creatures with changeling have all creature types. This plays into the tribal mechanics which grant bonuses to creatures of certain types. Though these changelings counts as humans for the purposes of the rules, no humans are found in the world of Lorwyn, or are printed on the cards. This marks yet another fundamental change of the game, as this was the first set to have no humans since their introduction as a creature subtype in "Mirrodin". (Although humans had been in all sets since the beginning of the game, they did not have their own subtype until "Mirrodin", instead only having subtypes based on their classes.) However, several of the planeswalkers, although they have no creature type, are physically humans. The "Lorwyn" block features the new champion, clash, evoke, and hideway. When a creature with Champion [a type] comes into play, it is sacrificed unless another creature of that type the player controls is removed from the game (that card is returned to play when the card with champion leaves). Clash involves two players revealing the top cards of the libraries. The person who reveals the card with the highest mana cost wins the clash and gets a bonus on the card played. If a creature is played by paying its Evoke cost, it is sacrificed when it comes into play. Hideaway, which appears on a cycle of rare lands, lets the player "hide" (exiling facedown) a card "away" for later. The new mechanics introduced in Morningtide are prowl, kinship, and reinforce.