Goddidit is one of the masterstrokes and trump-cards that creationists or other biblical literalists have at their disposal when debating points with naturalists and rationalists. It proposes that anything is and was possible because of the omnipotence of God - specifically the ability to bend the laws of time, logic and physics. This means that arguments that focus on the feasibility of a global flood for instance - complicated analyses of how much water would be required, if food could be provided for Noah's animals and the construction of his ark - can be swept away and ignored.
The concept of 'God did it' can be used to create unfalsifiable theories. A creationist need never doubt creation because God could have made anything. It may also be used as a euphemism to indicate something that cannot yet be explained by natural laws, most likely due to lack of information or knowledge.
One of the main reasons that the argument is popular is its apparent simplicity. It is essentially the simplest possible explanation for everything that happens in the universe - why bother with complex equations, evidence or anything when Goddidit will, in one word, sufficiently explain everything in the known universe? It is, thus, the answer to every and all questions taken to their extreme end (although if you're wondering how speaking the universe into existence actually works, you're a heretic and should shut up and go away).
Despite the convenience of the Goddidit explanation, entire reams of literature have been written by creationists to avoid it, attempting to present a scientific-sounding narrative instead, with Goddidit called in to whitewash over the flaws.
There is a massive issue of whether Goddidit is simple in the way that this parsimonious approach renders it correct. On the one hand, it is possible for a truly omnipotent being to do absolutely anything, so any unexplained phenomenon can be attributed to God's power and no complex natural explanations are needed. This is quite good for fundamentalists or creationists that need to justify lots of inconsistent data. On the other hand, Goddidit certainly begs the question of God's existence, and from the viewpoint of Occam's Razor, this is one massive assumption; the sort of assumption that should be avoided. From the view of simplicity, a creator would have to be incredibly complex, more complex than the universe, so invariably, a naturalistic explanation can only be simpler.
 Explanatory power
Recall an old science joke that gets this point across nicely:
“”A research student came to his supervisor with a graph showing the latest experimental results. The old wizened academic looked at it for a moment before saying "Aha! This makes perfect sense!" before rattling off his explanation of why the graph made sense. The student thought for a moment before noticing the mistake. "Oh, sorry" she said, "I had it upside-down!". The research student took the piece of paper, inverted it, and handed it back to the professor. After a second or two, he spoke again. "Aha! This makes perfect sense!"
The "goddidit" card can be used to effectively explain any phenomena presented. Take the YEC variant of "flooddidit" for a moment: Why is the Sahara a desert? The flood; Why is the Grand Canyon a canyon? The flood. Two completely different pieces of evidence with the same explanation. However, something that remains the same no matter what evidence is presented is no real explanation at all. A creationist or religious apologist putting forward "goddidit" as an answer has made no attempt to make a model of what such a belief entails, and what they could observe from it. While this works well in someone's own head to protect themselves from ever being wrong - and suffering cognitive dissonance - it means that they have no chance at adapting their views to suit reality, and actively try to prevent such a thing happening. While it's fair enough to say people are allowed to believe what they want, it's worth questioning the value of an idea like this.
 Deus ex machina
A deus ex machina (Latin for "god from the machine") is an improbable plot device that has been employed in fiction (often in the fantasy genre) to abruptly resolve problems within a story, and operates in a very similar fashion to Goddidit and the god of the gaps argument. Ad hoc reasoning may be employed in attempts to justify the intervention, since these events by their nature will often appear inconsistent with the narrative.
The phrase is Latin, but the concept is Greek in origin, and derived from the practice of introducing divine intervention into stories that have reached some kind of impasse. In Greek theatre, actors representing the gods would be winched onto the stage from a crane (hence the "machine" in this phrase). The gods of Greek mythology were highly anthropomorphic, like Yahweh of the Old Testament, and would meddle frequently in the affairs of mortals. This in some ways helped justify the arbitrary actions of gods in Greek plays, but overuse of this construct could lead to poorly structured stories with little scope for clever twists. It is difficult for readers to feel any sense of concern for characters in difficulties if they know that a convenient deity was always waiting in the wings.
Conventional storytelling usually has an element of justice: good characters overcome difficulties, and wicked or corrupt characters get their comeuppance. Often this occurs organically through strengths or flaws of the characters determining the outcomes of their interactions, but in deus ex machina solutions, the tensions are resolved by an unexpected factor which (usually) restores the balance in a similar way. In the case of gods, justice was imposed from above, rather than by the protagonists.
- Mormonism: Joseph Smith, the main prophet of Mormonism, had originally provided translations of mysterious golden plates he claimed had been given to him by the angel Moroni. Martin Harris, his supporter, had borrowed the translated works but then lost them. If Smith were truly translating from golden plates then he should have been able to repeat the translation process in order create something very similar to his original work. However, Smith introduced a deus ex machina by claiming that God had told him not to re-translate the missing works. Some believe that Harris's wife, Lucy, had deliberately hidden Smith's translated work in order to expose him as a fraud when he'd obviously be unable to recreate the missing manuscripts.
 See also
- Act of God
- Escape hatch
- God of the gaps
- Magical thinking
- Essay:What "Goddidit" means — an essay written to defend the use of the term on A Storehouse of Knowledge.