This repository contains items (i.e., puzzles) and item-level statistics described in: Chierchia, G., Fuhrmann, D., Knoll, L. J., Pi-Sunyer, B. P., Sakhardande, A. L., & Blakemore, S. J. (2019). The matrix reasoning item bank (MaRs-IB): novel, open-access abstract reasoning items for adolescents and adults. Royal Society Open Science, 6(10), 190232. DOI: https://doi.org/10.1098/rsos.190232 **Reuse:** Researchers may use any of the materials provided here for academic and non-commercial purposes only as they are either owned by or licensed to the researchers, their institutions or Cauldron Science. In relation to such use we ask that you cite the paper referenced above. The materials are provided for use at your own risk and neither the researchers, their institutions, nor Cauldron Science provide any warranties of any kind nor does any of them accept responsibility for any conclusions that you draw from their use. Please note that our task is not an IQ test. It is not intended to be used to determine someone’s intelligence or cognitive ability in, for example, educational, clinical or commercial contexts. This is because we do not have population norms for our task, so it does not generate an IQ score.