Generation and Analysis of Confounded and Fractional Factorial Block Designs R package lfebd3 version 0.1.0 Provides tools to generate and analyze 3-level linear factorial block designs, including complete factorial layouts, fractional factorial layouts, confounded factorial layouts, and design-characteristic summaries. The package includes utilities for recursive ternary construction, defining-contrast identification, alias/confounding summaries, incidence matrix construction, and design optimality diagnostics.The methodological framework follows foundational work on Gupta (1983) <doi:10.1111/j.2517-6161.1983.tb01253.x>. These methods assist in selecting, comparing, and studying factorial and fractional factorial block designs for large experimental situations. Software Imports: MASS, Matrix, stats, utils Suggests: testthat (>= 3.0.0) Sukanta Dash <sukanta.iasri@gmail.com> Comprehensive R Archive Network (CRAN) Vankudoth Kumar [aut], Sukanta Dash [aut, cre], Med Ram Verma [aut] GPL-3 2026-04-24 application/tgz https://CRAN.R-project.org/package=lfebd3 doi:10.32614/CRAN.package.lfebd3