Plausible deniability (PD) is a linguistic strategy that consists in intentionally conveying content in such a way that the intention can later be denied. PD is essential in the success of e.g. covert threats (“It would be a shame if something were to happen to you”), indirect insults (“I admire your courage for wearing that dress”), or sexual advances (“Would you like to come up for a coffee?”). A rigorous, scientific account of PD therefore can shine light on cases of language use in uncooperative of otherwise socially complex scenarios. A scientific account of PD as a communicative strategy is most naturally coached in the framework of Gricean pragmatics, where communication is reduced to a special case of interaction between rational agents. The current cutting edge of this reductive approach uses a combination of computational cognitive modelling, most importantly the Rational Speech Act (RSA) framework, and experiments. However, PD presents several methodological challenges for current techniques. First, in line with traditional Gricean pragmatics current models assume that interlocutors by and large share their goals (Grice's cooperative principle), while PD is often motivated by a goal misalignment. Second, current models of language use do not model social norms, which play a crucial role in what makes PD a popular strategy. Third, the current explanatory models of pragmatics require a manual specification of all the features of the context which are open-ended, e.g. the possible utterances and states. In this context, PlauDe has two fundamental concurrent objectives. The first is to develop a unified scientific account of PD as a rational communicative strategy that can subsume the disparate variety of cases of PD. The second is to enrich current models of pragmatics with the mechanisms that are needed to make sense of PD, and to open-end them. PlauDe has three main pathways to scientific impact. First, techniques to open-end current explanatory models of pragmatics can be applied to phenomena other than PD, and can therefore have an impact in the field of computational pragmatics. Second, research on PD fits within a recent wave of interest in socially sophisticated language within the field of pragmatics. Third, understanding PD can be a springboard to better models of the interaction between language use and social norms, extending computational pragmatic beyond its traditional Gricean assumptions.
