Territoriality and the factors that influence the outcome of animal contests are easy to study in a lab using convict cichlid fish (Archocentrus nigrofasciatus). I present a two-week laboratory experiment suitable for high school and college students. In the first week, students observe resident and intruder convict cichlids interacting in the presence of flowerpot territories, allowing them to develop hypotheses about factors that might determine the outcome of contests over resources, including relative size of competitors (“resource holding potential” hypothesis) and ownership (“resource value” hypothesis). They then work with their teacher to design and set up an experiment to test these two hypotheses, providing specific predictions that would support each hypothesis. In the second week, students observe contests between each owner and a larger or smaller intruder. The winner is defined as the individual that spends the most time in the pot and bites more. Students graph their data and decide what statistics are most appropriate for analyzing their results. They determine which hypothesis is supported by their findings and present their findings in scientific paper format.