Are all officially recognized Scrabble words English?

Looking at the official complete two-letter Scrabble word list, I cannot help but wonder whether they are even based on real English words. Are they?

Note: I realize the answer to this question may start going into more of a Boardgames realm, so feel free to restrict your answer to a rigidly EL&U answer. I only need to know if the words are English, or if they are based on English. I am not asking here how they were chosen.

The main Scrabble tournament dictionaries are the Official Scrabble Players Dictionary and the Chamber's Dictionary (also known as Official Scrabble Words). Together they make up SOWPODS which is the most common Scrabble wordlist.

But these dictionaries are not intended to define the English language (they don't even include definitions) and if you want to know if a particular word is English I recommend looking it up elsewhere.

That being said, whether something is English is isn't really the job of a dictionary. Dictionaries just list words in use. This is even more so with regards to Scrabble. As you have noticed, some of the words are drastically uncommon. Some of the far reaching examples include letters in non-English alphabets and currencies from around the world.

Each Scrabble word appears in at least one standard American dictionary, so yes, everything is a real English word. There are some weird words in there, but English is a weird language.

Generally speaking, the words are essentially "English" if you extend that definition to include some transliterations/loans of words from other languages that are very occasionally used in specialist English, and a few words that are usually only known to speakers of particular dialects.

On the other hand, that doesn't mean at all that Scrabble dictionaries contain "all words of English" (or even all common words in certain fields). In my experience it can happen quite often that a word that's used every day by e.g. a programmer or somebody working in a particular field and seems like a "normal, common word" to them isn't in the "Scrabble dictionary".