Krikkit is a planet located in a dust cloud composed chiefly of the disintegrated remains of the enormous spaceborne computer Hactar.
Hactar was originally created by the Silastic Armorfiends of Striterax to design the Ultimate Weapon. Hactar produced a very, very small bomb that, when activated, would connect every star to every other star, cause them to all go supernova simultaneously and, thus, destroy the universe. The bomb proved dysfunctional because Hactar had designed it with a tiny flaw, reasoning that no consequence could be worse than that of setting the bomb off. The Silastic Armorfiends disagreed and disintegrated Hactar into a dust cloud.
Due to the dust cloud, the sky above Krikkit was completely black, and thus the people of Krikkit led insular lives and never realised the existence of the Universe at large. With the population thus prepared, Hactar disintegrated but still functional, built and crashed a model spaceship onto Krikkit in order to introduce its inhabitants to the concept of the Universe. Secretly guided by Hactar, the Krikkiters built their first spaceship, Krikkit One, penetrated the dust cloud, and surveyed the Universe before them. Unbeknownst to the Krikkiters, Hactar had been subliminally conditioning their minds to the point where they could not accept a Universe into their world view, with the intention of putting them into a similar mindset to that of the Silastic Armorfiends. Sooner or later, they would require an Ultimate Weapon, and this would allow Hactar to finally complete his purpose, something he had felt considerable guilt about not doing before. Upon first witnessing the glory and splendor of the Universe, they casually, whimsically, decided to destroy it, remarking, "It'll have to go." Aided again by the mind of Hactar, the Krikkiters built an incredible battlefleet and waged a massive war against the entire Universe. The Galaxy, then in an era of relative peace, was unprepared, and spent the next 2,000 years fighting the Krikkiters in a war that resulted in about two "grillion" casualties.
When Krikkit was eventually defeated, Judiciary Pag sentenced Krikkit and its sun to be sealed in a Slo-Time Envelope within which time would pass almost infinitely slowly until the end of the Universe, thus serving the dual purpose of protecting the Universe from Krikkit, and allowing the Krikkiters to enjoy a solitary existence in the twilight of Creation. Light would be deflected around the envelope, making it invisible and impenetrable. The Wikkit Gate, the key that would unlock the envelope, was disintegrated into time, and could therefore not be used to free the planet from the envelope ahead of time.
However, a Krikkit warship carrying deadly white robots of the kind used in the war escaped before the envelope was sealed, and, within a brief ten billion years, managed to reassemble the Wikkit Gate. The Gate was composed of the Steel Pillar of Strength and Power (Marvin the Paranoid Android's artificial leg), the Golden Bail of Prosperity (The Heart of Gold, the small golden box that makes the Infinite Improbability Drive function), the Perspex Pillar of Science and Reason (The Argabuthon Scepter of Justice; "Plastic Pillar" in the American version), the Silver Bail of Peace (The Rory Award For The Most Gratuitous Use Of The Word "Fuck" In A Serious Screenplay; The Rory Award for the Most Gratuitous Use of the Word "Belgium" in a Serious Screenplay in the American version), and the Wooden Pillar of Nature and Spirituality (The reconstituted ashes of the stump signifying the death of English cricket: see The Ashes).
The robots unsealed the envelope, but Arthur Dent, Slartibartfast, Trillian, and Ford Prefect, with the unintentional help of Marvin, were able to disperse Hactar's particles, freeing the Krikkiters from his continued influence, and thus saving the Universe. Arthur then went to live on Krikkit for three years, before leaving for an unexplained reason. Krikkit also managed to leave other marks besides the destruction of numerous worlds: due to racial memories, the Earth sport of cricket and the pan-dimensional sport of Brockian Ultra-Cricket were based on the Krikkit Wars. Slartibartfast enjoys the game of cricket, but he notes that most sensible citizens of the galaxy find the sport to be in rather bad taste. The Krikketers are described as humanoid aliens who are charming and polite, despite their cosmocidal tendencies. They are capable of composing incredibly moving and poetic music. Some of the younger Krikketers are interested in developing sporting links with the rest of the Universe rather than destroying it.
- The 'Slo-Time Envelope' apparently reflected Adams' own feelings about the duration and pace of a typical cricket match.