Two borides, ScRu2B3 and Sc2RuB6 were obtained by argon-arc melting of the elements followed by annealing at 800 C. ScRu2B3 exhibits a new structure type with the space group Cmcm (a=3.0195(2) Å, b=15.4056(8) Å, c=5.4492(3) Å; single crystal X-ray data; RF2=0.0105). Sc2RuB6 adopts the Y2ReB6-type structure (space group Pbam; a=8.8545(2) Å, b=11.1620(3) Å, c=3.4760(1) Å; single crystal X-ray data; RF2=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 B63 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 Sc-Ru-B system at 800 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 I41/acd (no. 142), a=7.3543(2) Å, c=14.92137(8) Å). Cell parameters and atomic coordinates have been refined for ScRu2B3, Sc2RuB6 and ScRu4B4 in the scope of 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.