Cruised on the Norwegian Jade in June and you can opt out although they don`t advertise it, you have to notify the reception on your last cruise day.
As it says on NCLs website:
A fixed service charge of U.S. $10 per person, per day (U.S. $5 for children aged three to 12; no charge for children under three) will be added to your shipboard account to cover these tips. In addition, an automatic gratuity of 15% is added to all drink bills and 18% added for all spa and salon bills. You may, if you wish to reward a particular individual, add an additional tip to these bills; however, there is no obligation to do so.
Yes, they are compulsary unless you can really really prove that you have not received the quality of service (which I doubt). And no, you do not have the choice of 'opting out' of paying the tips on RCI. I sincerely hope you did not leave that ship without paying the $9.75pp pd that is expected......
Sorry to correct you but RCI still have the 'opt in' system. You will receive a gratuity sheet part way through the cruise. There will be the the recommended amounts for cabin steward, table waits etc. with a 'tick box' for each & a further box to adjust up or down as you see fit. If you hand the sheet in to the desk your account will be charged accordingly or if you do nothing with the sheet, you tip in the traditional manner & no charges will be added to your account. As a Footnote. Regarding NCL 'Mandatory Service Charge', reading through the recent revues on the NCL Jade weekend jollies, it appears people have been 'reducing' the service charge in the same manner as they were able to, prior to their change of Terms & Conditions.