I agree that
pardner is not a common word, and it won't be treated as such in future, but I dispute that it's quite as ludicrous a notion as forumites are suggesting.
The online Oxford description of the word as a non-standard spelling is obviously not the whole story. I prefer the Shorter Oxford's treatment:
noun. colloq. (orig. US). l18.
[ORIGIN: Repr. a pronunc. of partner noun.]
A partner, a comrade. Freq. as a form of address.
The word is found in a great many dictionaries, including the online Cambridge Advanced Learner's Dictionary and Thesaurus. Looking at the lists I considered in making the original assessment of common / rare,
pardner is found, oddly, in the "2 of 4" list derived from 4 ESL dictionaries from British publishers. The word, even more oddly, is
not in the "2 of 12" list based on US dictionaries. More recently, the creator of these lists, Alan Beale, has produced a list called 3of6game, derived from a mixture of US and British advanced learners dictionaries, which seems to me to be a fairly reasonable match to my idea of common words. This list includes
pardner.
Use of the word outside the US is not unknown, usually in a context relating to the American West. For example the OED cites Margery Allingham's brilliant 1952 crime novel,
Tiger in the Smoke: "'Now, pardner,' he said. They were both great readers of Westerns." A 2008 article in the Melbourne
Age business section was headed "Howdy, pardner; nice to keep you company". The article compared taxation rules for partnerships and companies. In 2016 the
Liverpool Echo reported that, "A star line-up of homeless hounds at Dogs Trust Merseyside are hoping it's time to say howdy pardner to their new owners." The dogs were all named after country singers.
Despite these occasional appearances, I accept that players - including perhaps some American players - may doubt that
pardner is actually a word, thinking of it rather as no more than a representation of how some people pronounce
partner. So it will be rare from now on.