High-resolution neutron diffraction experiments at scattering vectors up to 40 Angstrom (-1) have been carried out for the Ag2S-As2S3 glassy system in order to find differences in the network structural organisation within the percolation and modifier-controlled domains. No significant changes in the short- and intermediate-range order are found in the critical percolation region (x less than or equal to 1.2 at.% Ag): the intensity and position of the first sharp diffraction peak (FSDP) exhibit relatively small changes as a function of the silver content, and the trigonal arsenic local coordination and two-fold coordinated sulphur species remain essentially intact. These observations agree very well with a model of host network-dependent percolative ion transport. In the modifier-controlled domain (x > 10-15 at.% Ag), one observes nearly complete disappearance of the FSDP at 1.25-1.35 Angstrom (-1) and remarkable changes in the short-range order, in particular, characteristic Ag-Ag correlations at approximate to 3 Angstrom, indicating a predominant role of Ag-containing structural units in the modified network organisation. These structural units and their interconnections seem to be similar for many silver-rich chalcogenide glasses, in which the Ag+ ion transport depends on the Ag content but not on the host matrix.