This study is part of primary prevention and knowledge mobilisation for a high-risk group; women who smoke during pregnancy. This is in response to practice and policy drivers, indicating that although NICE guidance 26 is embedded into practice, rates of smoking in pregnancy continue to be of concern. By developing this computer model, based on Evolutionary Game Theory, we will establish the first stage in a prevention and behaviour change intervention that may improve smoking cessation outcomes for pregnant women. We anticipate it will be available for use in local and national healthcare systems and has the potential to become a model for other health behaviours.