What is the consequence of failing to accept an offer to settle?

An award of double costs punishes an unsuccessful litigant for failure to accept an offer to settle which she ought, in all the circumstances, to have accepted. Costs rules exist to deter frivolous actions or defences; encourage conduct that reduces the length and expense of litigation; and discourage conduct that has the opposite effect. The rules relating to costs also encourage litigants to settle whenever possible and have “a winnowing function in the litigation process” by requiring litigants to carefully assess the strength or weakness of their cases through the course of the litigation: Hartshorne v. Hartshorne, 2011 BCCA 29 at para. 25.