Two borides, ScRu2B3 and Sc2RuB6, were obtained by argon-arc melting of the elements followed by annealing at 800 degrees C. ScRu2B3 exhibits a new structure type with the space group Cmcm (a = 3.0195(2) angstrom, b = 15.4056(8) angstrom, c = 5.4492(3) angstrom; single crystal X-ray data; R-F(2) = 0.0105). Sc2RuB6 adopts the Y2ReB6-type structure (space group Pbam; a = 8.8545(2) angstrom, b = 11.1620(3) angstrom, c = 3.4760(1) angstrom; single crystal X-ray data; R-F(2) = 0.0185). ScRu2B3 displays an unusual intergrowth of CeCo3B2- and AlB2-related slabs; a striking feature is a boat configuration of puckered boron hexagons within infinite graphite like boron layers (63 nets). Sc2RuB6 presents two-dimensional planar nets of condensed boron pentagons, hexagons, and heptagons sandwiched between metal layers. In Sc/Y substituted Y2ReB6-type, Y atoms are distributed exclusively inside the boron heptagons. Exploration of the ScRuB system at 800 degrees C including binary boundaries employing EPMA and powder X-ray diffraction technique furthermore rules out the existence of previously reported ScRuB4 but confirms the formation and crystal structure of Sc2Ru5B4. ScRu4B4 forms in cast alloys (LuRu4B4-type structure; space group I4(1)/acd (No. 142), a = 7.3543(2) angstrom, c = 14.92137(8) angstrom). Cell parameters and atomic coordinates have been refined for ScRu2B3, Sc2RuB6, and ScRu4B4 in the scope of the generalized gradient approximation. Ab initio electronic structure calculations indicate a moderate electronic density of states at the Fermi level situated near the upper edge of essentially filled d-bands. Electrical resistivity measurements characterize ScRu2B3 and Sc2RuB6 as metals in concord with electronic band structure calculations.