This document discusses the seismic behavior of steel structures with different bracing systems and irregularities. It analyzes 3D models of 8, 10, and 12 story steel buildings with rectangular and C-shaped plans in zones III, IV, and V, with and without X-bracing and K-bracing systems. The models with vertical irregularities are analyzed for lateral displacement and story drift. Results show story drift increases with zone intensity, number of stories, and vertical irregularity. Bracing systems reduce drift compared to no bracing, with K-bracing having slightly higher drift than X-bracing. Lateral displacement and story drift also increase from lower to higher zones due to increasing seismic intensity.