Uncertainties of the eRASS1 photometric cluster redshifts. The black dots are the formal uncertainties $\delta z_{\lambda }^{\mathrm{f}\mathrm{m}\mathrm{l}}$ calculated by eROMaPPer as the standard deviation of the redshift posterior P(z). We adopted them as the final redshift uncertainties z_λ,err. The dashed red line is the mean of the upper and lower empirical uncertainties $\delta z_{\lambda }^{\text{spec\hspace{0.17em}}}$ derived from the comparison to the spectroscopic cluster redshifts. The continuous red line is the absolute redshift bias |Δz_λ|.