19 October 2021
First, to get it out of the way, the word Scot, referring to a person from Scotland, is an entirely different word and has nothing to do with scot-free. Second, in the past, there was a common variant shot-free. That variant is much rarer now, but it can still be heard in certain places.
Note: the standard practice in linguistics is to use angled brackets, < >, to mark spellings and slashes, / /, to mark pronunciations.
Scot and shot come from the Old English sceot, meaning an arrow or other type of missile, a rapid movement, or a payment. Correspondingly, the Old English verb sceotan meant to shoot an arrow, to move quickly, or to make a payment. The sc- in Old English was pronounced as /ʃ/, similar to the <sch> spelling in modern German or the <sh> spelling in Present Day English. The payment senses of scot, shot, and to shoot have largely disappeared, except in the fossilized idioms of scot-free and shot-free, but you can still find the payment meaning in particular contexts and dialects. But in the twelfth century, the early Middle English period, the /skɒt/ pronunciation, with a hard <c> or /k/ begins to appear. This was apparently due to influence from cognates in Old Norse that had the /k/ phoneme—the Danes occupied and settled in much of North and Eastern England in the late Old English period, and by the twelfth century that linguistic influence was starting to appear in English writing. For several centuries, both the /sk/ and /ʃ/ pronunciations were used interchangeably.
Then in the later Middle English period we start seeing the <sh> spelling to represent the /ʃ/ pronunciation. And in the Early Modern period, we see the two forms start to diverge semantically. The /sk/ pronunciation, or scot, came to be used for the tax and payment senses, while the /ʃ/ pronunciation, or shot, came to be used for the ammunition and movement senses, with an exception being the word shot-free, which is synonymous with scot-free. And in Present-Day English, scot has largely dropped out of the active vocabulary, being used mostly in historical contexts and in scot-free.
Scot-free appears as early as 1054 CE, when it appears in a bequest of land to Westminster Abbey sanctioned by Edward the Confessor:
Ic cyðe eow þæt ic wille þæt þæt cotlif Leosne þe Ætsere ahte & becwæð Criste & Sancte Petre into Westmynstre ligge nu ðider inn to ðæra muneca fodan mid eallum ðæra ðingum þe þær to hyreð on wude & on felde, on mæde & on wætere & on ealle oðre þingum scotfreo & gafolfreo on scire & on hundrede swa ful & swa forð swa he hit Sancte Petre becwæð & ic ðes fullice geuðe.
(I say to you that that my will is that the estate of Lessness that Ætsere owned and bequeathed to Christ and to Saint Peter into Westminster now belongs to that habitation for the monk’s food with all the things that there belong to it in wood and field, in meadow and in water, and all other things scot-free and tax-free in shire and in hundred as completely and as freely as he bequeathed it to Saint Peter and I fully consent to this.)
By the seventeenth century, scot-free was being used more generally to mean free of penalty. We see this expanded sense in a 1622 translation of Matheo Aleman’s The Rogue, in a discussion about legal disputes over debt. One speaker contends that the plaintiff always gets the better of the defendant, so it is usually cheaper and easier to just pay, even if the debt is not legitimate:
But when such things come in question, the accuser hath commonly the better of the accused; the plaintiffe will bee sure to fare well, how ere it goe with the defendant; he hath that he lookes for, he cares for no more; for it is in this, as at Best be trusted, amongst Costermongers, the first speaker scapes scot-free
Sources:
Aleman, Matheo. The Rogue: or the Life of Guzman de Alfarache, part two of three. London: Printed for Edward Blount, 1622, 231.
Harmer, F.E. Anglo-Saxon Writs. Manchester, England: Manchester UP, 1952, 343. London, Westminster Abbey Munimwnra xi.
Middle English Dictionary, 2019, s.v. shot, n., scot, n.(2).
Oxford English Dictionary, third edition, June 2011, modified September 2021, s.v. scot-free, adj., modified December 2020, scot, n.2; second edition, 1989, shot-free, adj., shot, n.1, shoot, v.