how do I do not allow an opportunity stage to be set to close based on a condition?

if the status of the opportunity is of value x then the opportunity stage cannot be set to Closed.

It’s a long thread, but I think you’ll find what you need here: http://community.skuid.com/skuid/topics/how_do_i_render_custom_picklist_values

Alternatively, I believe you could set some kind of validation rule in salesforce.

thanks Matt