What if an election is tied? Apparently it is not that unusual, at least in contests with relatively small electorates. FiveThirtyEight tells of some recent US cases. It also cites a study by Casey B. Mulligan and Charles G. Hunter that says:
between 1898 and 1992 there were no tied elections for [US] federal office and only one (New York’s 36th District in 1910) that was decided by one vote. Only twice has a general election for a state legislative seat resulted in a tie: a Rhode Island state Senate race in 1978 and a 1980 New Mexico state House race. The former was decided by a special election, the latter by a coin flip.
I understand by way of Yusaku Horiuchi that ties for the last seat are fairly common in Japanese municipal elections, where SNTV is used.
What about other countries that readers may have familiarity with? And do most jurisdictions have clear rules of what to do in even of a tie? The FiveThirtyEight post refers to some cases where there were no such rules, and the council or other body had to make up a procedure.