Destructable wall building blocks and castle pieces

This is a very loose fitting stacking wall block similar in concept to the popular toys that are out there.  It can be stacked to form a wall, pyramid, building, or other similar structure.  The difference between these blocks and others is that they are designed to be loose fitting, so that the wall fall or crumble spectacularly when hit with any projectile.  

Originally conceived as part of a larger game where you build structures and then destroy them with catapults, ball shooters, crossbows, or other common shooting toys like nerf blasters.

This set does not include figures but there are plenty of excellent figures available from designers on thingiverse, my favorite to use are here:
https://www.thingiverse.com/BriteMinis/designs

The wall is designed using OpenSCAD so it can easily output .stl files of different sizes or with different features.  The easiest version is the file "wall_block.scad" and you will just need to find the line "size = 2;" toward the top and change this to the desired size.  1, 2, and 4 are common sizes but 6 and 8 can also be used.  

The subsequent lines, base_width, base_height, and curve_size can also be modified if you want to change the scale, but then you will also likely need to change the hole heights to keep the blocks stackable with minimum effort.  

The file "wall_block_half.scad" has more features such as the ability to make 2-to-1 blocks for building tapers into the wall or making bricks with flat tops.

These blocks are designed to be printed using high speed settings and use minimal filament.  

Many printers can print in the default orientation without infill or supports, and with minimal perimeters.  

In Slic3r PE, I set Layer Height to 0.2, Vertical Shells / Perimeters to 1, Horizontal Shells / Solid layers to 3 (Top and Bottom), and check "Extra perimeters if needed", "Ensure vertical shell thickness" and "Detect bridging perimeters".  In Infill, set the Fill density to 0% and the Fill angle and Bridging angle to 0 (leaving these at 45 degrees can sometimes cause bridging problems).

Update 12/22/2019 - I added a few variants specifically for building castle-type structures.  wall_block_front_parapet.scad is used to generate a top-block with a flat top and a front castle wall that figures can "hide" behind, square_tower_top.scad is used to generate a square tower top that figures can stand on.  Unlike the wall blocks, these require some minimal infill to print, a good starting point is cubic infill at 5%.  Also, square_tower_top prints best at 45 degrees infill angle (rather than 0 degrees).