Ravnica block

The Ravnica block is the 11th Magic: The Gathering block, comprising of the large expansion Ravnica: City of Guilds and the two small expansions Guildpact  and Dissension. The block was released in 20052006.

Development codenames
The development codenames for Ravnica block expansions are "Control", "Alt", and "Delete".

Marketing
Ravnica block fat packs featured specially designed life counters with artwork from the sets instead of the spindown life counters normally found in fat packs.

Themes
Thematically, the Ravnica block was multicolor-centered and, thus, was the spiritual successor to the Invasion block of 20002001. The Ravnica block was the first block to introduce the "guild model", wherein a number of guilds, each of which with its own cards and abilities and/or keywords, would be as introduced in an expansion and be as developed and complex as they would be (until returning to the plane with Return to Ravnica block), rather than the traditional model of expansions, wherein abilities and/or keywords would be introduced in the first of usually three expansions and then progressively increase in complexity throughout the block. Four guilds (Boros, Dimir, Golgari, Selesnya) were introduced in City of Guilds, three more (Gruul, Izzet, Orzhov) were introduced in Guildpact, and the final three (Azorius, Rakdos, Simic) debuted in Dissension.

Mechanics
The keywords introduced in the Ravnica block are:

In addition to these 10 keywords, the Ravnica block was the first block to feature hybrid mana costs and hybrid cards. Each of Ravnica's 10 guilds featured three hybrid cards, one at each level of rarity as of then; common, uncommon, and rare.

Mega cycles
Ravnica block features 11 10-card guild mega cycles, with one card per guild, and one 20-card guild mega cycle (the "imbalanced gold card" cycle) distributed across Ravnica: City of Guilds, Guildpact, and Dissension.