A 12-sided die in the shape of a trapezorhombic dodecahedron, aka the dual of the triangular orthobicupola. This D12 has three pairs of parallel trapezoid faces and six non-parallel rhombus faces. When the die lands on a trapezoid face, what you see from above is another trapezoid face and the value of the roll is the number engraved on this face. When the die lands on a rhombus face, what you see from above is an edge and the value of the roll is the sum of the two numbers on both sides of the edge. All the numbers from 1 to 12 can be generated. This is probably not a fair die.