Slug (coin)

A slug is a counterfeit coin that is used to make illegal purchases from a coin-operated device, such as a vending machine, payphone, parking meter, transit farebox, copy machine, coin laundry, gaming machine, or arcade game. By resembling various features of a genuine coin, including the weight, size, and shape, a slug is designed to trick the machine into accepting it as a real coin.

Though slug usage is a violation of the law, prosecution for slug usage is rare due to the low value of the theft and the difficulty in identifying the offender. Offenders in casinos are most likely to be prosecuted, as casinos have high levels of video surveillance and other security measures, and are more proactive in enforcement.

Losses caused to vendors by slug usage may be the result of the loss of sales, the absence of revenue following the distribution of merchandise that was obtained at the vendor's expense, or the loss of cash that is distributed by the machine for overpayment with slugs. Honest customers may also suffer losses when change returned to an honest customer for overpayment is in the form of a slug rather than a genuine coin.

In some cases, a slug can be a genuine coin used in another country, with or without knowledge of the user. One example was the interchangeable use of Australian and New Zealand 5c, 10c and 20c pieces in both countries, from 1967 until 2006 (when New Zealand coins were redesigned). These coins were of the same material and size with near identical obverses, so could circulate outside their home country for some time, although the New Zealand coins were worth about 20% less, potentially resulting in a small gain (to those passing them) in Australia and a similar loss in New Zealand.

The Canadian quarter was also accepted by at least some US vending machines interchangeably with the US quarter until at least 2001. The usefulness of this to offenders varied greatly over time; during the 1970s and 1980s, the Canadian and US quarters were very similar in value.

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