This repository provides access to the dataset of geometrical digital twins of multi-leaf rubble stone masonry walls for the blind prediction competition on the monotonic in-plane shear–compression response of multi-leaf masonry walls. It also includes the competition guidelines, instructions, submission templates, and preliminary mechanical properties of the wall constituents. The competition focuses on predicting the structural response of walls with diverse microstructures before experimental testing, which will take place in May 2026 at the Structural Engineering Platform (GIS), EPFL, Lausanne, Switzerland. A README file details the dataset structure and folder contents. For more information, visit the competition webpage: https://mati-shah.github.io/Blind-prediction-competition-/.