How uncertainty data is visualised can play a significant role in analysis and decision-making, especially involving multiple stakeholders. Even when only one person is responsible for every aspect of analysis and decision-making, visualisation may still play a significant role in how uncertainty is understood-i.e. in how the decision-maker 'communicates uncertainty to themselves.' Using the right visualisation tools can have a positive impact on decision quality. But this positive impact should never be taken for granted: visualisations can also have unexpected side-effects, and there is the risk that they can be misinterpreted or otherwise misused. This primer, published by the Analysis under Uncertainty for Decision-Making network (AU4DM), summarises the current