•The existing breakage models are found incompetent in oblique impact.•Literature impact breakage databases are collected for model assessment.•A proposed oblique impact model shows its novelty in unifying breakage curve.•The oblique impact model can be integrated with any normal impact breakage models. Many experimental and numerical studies have been performed on the impact breakage of particulate solids, leading to a variety of impact breakage models developed to predict breakage probability. Ideally, impact breakage models would be mechanistic in nature, mathematically simple and inclusive of critical breakage parameters. In this paper, a critical review of the most widely used impact breakage models is presented, with the conclusion that the majority of existing breakage models inadequately predict breakage probability under oblique impact. In this work, a novel oblique impact model is proposed where the effect of impact angle is considered by the equivalent velocity. A breakage database compiled from the literature is deployed to interrogate the validity of the proposed model across a variety of oblique impact circumstances. In this way, the new oblique impact model is shown to provide excellent predictions of breakage probability, requiring only one set of fitting parameters under various impact angles. The unique feature of this oblique impact model is not necessarily required to be used with any specific normal impact breakage models, but can instead be universally applied with any of the assessed normal impact breakage models to establish unified breakage master curves for any oblique impact.