Fraction of each gas phase relative to the total gas mass (left) and the absolute gas mass for each phase (right) as functions of halo mass (x-axis) across all halos and clusters of TNG300 at z = 0. We divide gas into cool (first row, blue), warm (second row, purple), and hot (third row, orange) components. The color intensity indicates the number of halos per pixel. The black markers are the median in both gas fraction or gas mass and halo mass for mass bins of width 1 dex from 10⁸ to 10¹⁵ M_⊙. The error bars denote the 16^th and 84^th percentile along both axes. More massive clusters host larger amounts of cool gas within their FoF halos, even though fractionally the contribution of cool and warm gas to clusters decreases with total mass.