Universal bricks
Universal brinks for building construction on Earth are usually made from clay, and the masonry is build from bricks and grout. Many identical bricks can be arranged to any big structure. Even domes can be made. On Mars it might not be possible to produce grout. This article wants to collect ideas how to make universal bricks that do not need grout.
Material
The brick can be made from sintered regolith, for example.
Six hole cube
The connection between the bricks is held by round sticks (from the same material). Three sticks for each brick are used to extend the construction in all three dimensions.