  We present the optical and UV emission line properties of 160 X-ray selected
AGN taken from the RIXOS survey (including Halpha, Hbeta, [OIII]5007, MgII2798
and CIII]1909). This sample is believed to contain a mixture of absorbed and
unabsorbed objects, with column densities up to 4e21 cm-2. Although the
distribution of the [OIII] EW for the RIXOS AGN is typical of optically
selected samples, the Balmer line EWs are relatively low. This is consistent
with the presence of a dust absorber between the broad and narrow line regions
(eg. a molecular torus), and intrinsically weak optical line emission. We find
Baldwin effects in CIII] and MgII, and a positive response of the MgII line to
its ionizing continuum. There is a strong correlation between the EW and FWHM
of MgII, which may be similar to that seen in other samples for Hbeta. We
demonstrate that this is consistent with models which suggest two line-emitting
zones, a `very broad line region' (VBLR) and an `intermediate line region'
(ILR). The correlation between EW and FWHM in MgII may be a physical
characteristic of the ILR or it may reflect a geometric dependence. We found no
correlation between the Hbeta FWHM and the slope of the X-ray spectrum, however
this may be due to the effects of dust absorption which suppresses the broad
Hbeta component, masking any relationship. The Halpha FWHM does tend to be
narrow when alpha_X is soft, and broadens as alpha_X hardens, although the
formal probability for this correlation is low (91 per cent). If the
distribution of alpha_X in the RIXOS sample reflects the level of intrinsic
absorption in these AGN, the data suggest a possible link between the velocity
of the Balmer line-emitting region and the amount of absorbing material beyond.
