The literature on strategic voting has provided evidence that some electors support large parties at the voting booth to avoid wasting their vote on a preferred but uncompetitive smaller party. In this paper we argue that district conditions also elicit reactions from abstainers and other party voters. We find that, when ballot gains and losses from different types of responses to the constituency conditions are taken into account, large parties still benefit moderately from strategic behaviour, while small parties obtain substantial net ballot losses. This result stems from a model that allows for abstention in the choice set of voters, and uses counterfactual simulation to estimate the incidence of district conditions in the Spanish general elections of 2000 and 2008.