Abstract A new algorithm for the responses of Eucalyptus species to fire was developed to be used in BRIND, an existing forest gap simulation model. After a fire, trees may be: (i) killed outright; (ii) have their above-ground parts killed but resprout from basal lignotubers; or (iii) continue to grow from undamaged and epicormic above-ground buds. Data collected after a fire in the Gudgenby region, Brindabella Ranges, southern Australian Capital Territory, indicate that tree size and vigour can be used to predict the response of individual trees. There was not enough information about fire intensity to estimate its effect on the response of trees. The new algorithm was tested using data from a 1982 fire in Bushrangers Creek, Brindabella Ranges. The predicted probabilities of stem death were similar to the field data.