can play this type of metagame and choose which rules apply during the game itself, potentially changing the level of difficulty. Such metagames include campaign role-playing games like Halo 3. Complex card or board games, e.g. poker or chess, are also often referred to as metagames. According to Nigel Howard, this type of metagame is defined as a decision-making process that is derived from the analysis of possible outcomes in relation to external variables that change a problem. Abstraction and self-reference Any subject can be said to have a metatheory, a theoretical consideration of its properties – such as its foundations, methods, form, and utility – on a higher level of abstraction. In linguistics, grammar is considered to be a metalanguage: a language operating on a higher level to describe properties of the plain language, and not itself. Etymology The prefix comes from the Greek preposition and prefix meta- (μετα-), from μετά, which means "after", "beside", "with", "among" Other meanings include "beyond", "adjacent" and "self", and it is also used in the forms μετ- before vowels and μεθ- "meth-" before aspirated vowels. The earliest form of the word "meta" is the Mycenaean Greek me-ta, written in Linear B syllabic script. The Greek preposition is cognate with the Old English preposition mid "with", still found as a prefix in midwife. Its use in English is the result of back-formation from the word "metaphysics". In origin Metaphysics was just the title of one of the principal works of Aristotle; it was so named (by Andronicus of Rhodes) because in the customary ordering of the works of Aristotle it was the book following Physics; it thus meant nothing more than "[the book that comes] after [the book entitled] Physics". However, even Latin writers misinterpreted this as entailing metaphysics constituted "the science of what is beyond the physical". Nonetheless, Aristotle's Metaphysics enunciates considerations of a nature above physical reality, which one can examine through certain philosophy – for example, the existence of God. The use of the prefix was later extended to other contexts, based on the understanding of metaphysics as meaning "the science of what is beyond the physical". Early use in English The Oxford English Dictionary cites uses of the meta- prefix as "beyond, about" (such as meta-economics and meta-philosophy) going back to 1917. However, these formations are parallel to the original "metaphysics" and "metaphysical", that is, as a prefix to general