Tribal

Tribal is a card type first introduced in Future Sight, and expanded upon in the Lorwyn block. Creatures and tribals share the same set of subtypes. Cards referring to specific creature types may also affect tribals. Tribal returned in Rise of the Eldrazi.

No longer supported
R&D no longer supports the tribal card type. Mark Rosewater announced its death knell, when it wasn't used in Innistrad (which had a strong tribal subtheme). He stated that tribal was problematic everywhere R&D used it because they couldn't go half in, which resulted in a lot of extra words for very little actual use. On the other hand, mechanically caring about creature types is still very much alive.

Tribal made a small reappearance on the test card Form of the Mulldrifter, in the Mystery Booster set.

Subtypes
The subtype for tribals is called creature type and shared with creatures.

Rulings

 * Tribal is not a permanent type. However, a tribal card can become a permanent if another of its types allows it to do so.
 * Many Lorwyn cards refer to specific creature types. These cards may affect tribals, depending on what they say and what they do. For example, using "Goblin" as our creature type:
 * If a card uses "Goblin" as a noun (that is, without following it with a word like "card" or "spell"), it actually means "Goblin permanent." It can affect any Goblin permanent in play, including a Goblin tribal.
 * If a card says just "Goblin creature," it can affect only a Goblin creature in play. It can't affect a tribal.
 * If a card says "Goblin card," it can affect any Goblin card not in play, including a Goblin tribal card.
 * If a spell asks whether you control a Goblin, it's asking whether you control a Goblin permanent. It won't count Goblin spells you control (including itself).
 * If a card with multiple types has one or more subtypes, each subtype is correlated to its appropriate type.
 * When one or more of a permanent's subtypes changes, the new subtype(s) replace any existing subtypes from the appropriate set (creature types, land types, artifact types, enchantment types, spell types, or planeswalker types). It won't affect the subtypes from any other set, and it won't affect the permanent's types.
 * If a permanent ceases to be one of its types, the subtypes correlated with that type will remain if they are also the subtypes of a type the permanent currently has; otherwise, they are also removed for the entire time the permanent's type is removed.
 * The Onslaught card Artificial Evolution can change the creature types of a tribal.
 * Many older cards have received errata in the Oracle card database to work sensibly with tribals. For example, instant and sorcery cards can't come into play. If an older card was printed with a wording that allowed you to put a Goblin card into play, it now specifies that you can put a Goblin permanent card into play.

Trivia

 * Tribal was featured as rules card 5 of 5 in the Lorwyn set.
 * There are 55 tribal cards, featuring seventeen creature types (Eldrazi, Elemental, Elf, Faerie, Giant, Goblin, Kithkin, Lhurgoyf, Merfolk, Rebel, Rogue, Shaman, Shapeshifter, Soldier, Treefolk, Warrior, and Wizard).