Binary -verses occur when a pair of universes, multiverses, or other -verses partially combine, or form together. Travel between them becomes much easier, and beings from each -verse are often able to communicate freely. The event that creates a binary -verse can often be called a crossover or "merge", though sometimes -verses formed together and never "crossed over" at all. Similar to star systems, -verses can form larger groups like triple or quadruple -verses.