T HE WAYS IN WHICH political situations develop depend on how various participants respond to contested and problematical actions in them. In some cases ambiguous acts need to be clarified in order for supporters and opponents to calculate their next moves. In other cases acts that appear to shift the advantage in a situation may require special justification for other participants to accept or tolerate them. Some political acts may arouse suspicion as potential violations of the norms or articles of trust that bind participants together in a situation; under these circumstances an actor may have to offer special reasons, excuses, or normative interpretations to retain the support of a coalition or to maintain the opposition's commitment to fair play. In these and other instances of problematical political action, the outcome of the situation may depend on the actor's ability to suggest a compelling way for the act to be taken. The standard procedure for influencing responses to problematical political acts is to offer an account. Lyman and Scott have defined an account as "a statement made by a social actor to