Left panel: Distribution in the mass-redshift plane of all ACT SZ clusters in the KiDS effective area. Objects with no AMICO counterpart are displayed in red. Central panel: Distribution of the angular displacement between the centers of the matched detections between the ACT and AMICO samples for three different redshift intervals. The best-fit Rayleigh distributions are shown as dashed lines; the values of their corresponding σ_r are also reported in the legend. Right panel: Relation between the AMICO intrinsic richness, λ_*, and the ACT SZ-derived mass, M₂₀₀, for the matched objects. Data are color coded according to three different redshift intervals.