There is often debate here about the rules and rights of ambassador and Royal ambassador membership. Below are the relevant sections from the Members' Terms and Conditions. I also have had a shot at an interpretation. YMMV.

INTERCONTINENTAL AMBASSADOR STATUS

1. As a Priority Club Rewards member, you may also purchase InterContinental Ambassador status. Purchase of InterContinental Ambassador status entitles you to higher levels of recognition and to all published benefits of InterContinental Ambassador status valid only at InterContinental Hotels & Resorts properties worldwide. Standard Priority Club Rewards benefits apply when you stay at other hotels within the IHG family of brands - Crowne Plaza®, Hotel Indigo®, Holiday Inn®, Holiday Inn Express®, Express by Holiday Inn®, Staybridge Suites® and Candlewood Suites®.
2. If you have InterContinental Ambassador status, you are subject to all Priority Club Rewards Membership Terms and Conditions. Ambassador and Royal Ambassador status and Royal Ambassador referral certificate may not be transferred, bartered, or sold. Ambassador and Royal Ambassador benefits apply only to the member’s personal room.
3. Only Priority Club Rewards members may purchase InterContinental Ambassador status. Upon purchase of InterContinental Ambassador status, Priority Club Rewards members who have not achieved Gold Elite status will be automatically upgraded to the Gold Elite membership level. A non-Priority Club Rewards member who purchases InterContinental Ambassador status will automatically be enrolled in Priority Club Rewards at the Gold Elite membership level.
4. Priority Club Rewards membership and InterContinental Ambassador benefits are not transferable.
5. Priority Club Rewards members with InterContinental Ambassador status will be invited to renew every year. In order to continue receiving InterContinental Ambassador benefits, Priority Club Rewards members must pay an InterContinental Ambassador renewal fee every year prior to membership expiration.
6. The accrual of room nights towards Royal Ambassador status is not applicable in conjunction with airline and/or travel industry discounts or to long-stay residents at their long-stay hotel, defined as a continuous stay of 90 days or more.
7. InterContinental Ambassador benefits are not available to airline crew members for crew stays.
8. Complimentary Weekend Night Certificate: Upon purchase and renewal of InterContinental Ambassador status a Complimentary Weekend Night Certificate shall be awarded. Each Complimentary Weekend Night Certificate is valid for 6 months from the date of issue and is redeemable in conjunction with a minimum two-night weekend stay at any InterContinental Hotels & Resorts property hotel (not valid at any other IHG brands). The Complimentary Weekend Night Certificate is valid for a complimentary room night on second night of paid weekend stays. Weekend is determined as follows: Friday, Saturday and Sunday, except in the Middle East where hotels may define the weekend as Thursday, Friday and Saturday. Certificates are valid only for the member who has InterContinental Ambassador status, and are not transferable. Certificate is valid for room and tax only. Certificate cannot be used in conjunction with any other promotion. Rates openly available are not promotions. Where a member has made the reservation and purchased via Net Wholesaler/Inclusive Groups or through a web site other than an IHG web site, such as Priceline.com or Hotwire.com, or similar booking engines where the room rate is not viewable or publicly available at the time of booking, the hotel can decline the Complimentary Weekend Night Certificate. Reward Nights do not apply in conjunction with Complimentary Weekend Night Certificates.
9. InterContinental Ambassador Benefits: Upgrades to a Superior room will be assigned at check-in. A room one category higher than purchased will be assigned to InterContinental Ambassadors. Late Check-out Courtesy: InterContinental Ambassadors will be entitled to a late check out time of 4:00 pm. Airport Chauffeur Service is available with advance reservations and at published fares. When staying on Reward Nights, all Ambassador and Royal Ambassador privileges apply with the exception of upgrades, free Pay TV film per stay, 24 hour guaranteed room availability, 8:00am early check-in and complimentary mini bar beverages.
10. Royal Ambassador Status: Royal Ambassador status is the highest level of status and entitles Priority Club Rewards members to additional benefits at InterContinental Hotels and Resorts. Royal Ambassador status is granted to Priority Club Rewards members by invitation and at Priority Club Rewards’ sole discretion. Priority Club Rewards reserves the right to limit the number of members with Royal Ambassador status. Guaranteed room availability for one room occupied by the Royal Ambassador with 24-hour advance reservation. Reservations must be made before 12:00 midday (local hotel time) 24 hours prior to intended arrival for room availability to be guaranteed. Only in exceptional circumstances where the hotel has been completely reserved by the Government and with explicit Priority Club Rewards approval, may a reservation be declined. Early check-in (8:00 am) shall be available to all Royal Ambassadors. Upgrade to an executive room or suite for Royal Ambassadors at check-in. In circumstances where an executive room or suite is not available at 8:00 am, the Royal Ambassador will be checked into an available room until the executive room or suite is available later on the day of arrival. Use of health club facilities (where available) shall be complimentary for Royal Ambassadors. Treatments such as massage, facials, manicure may incur charges. Complimentary beverages from the mini bar in the Royal Ambassador’s personal room only, and for in-room consumption by member only (benefit excludes non beverage items). Void where prohibited by law.
11. Priority Club Rewards membership and InterContinental Ambassador and Royal Ambassador benefits are provided where available, at the sole discretion of IHG, and shall be considered void where prohibited by law.
12. SCH reserves the right to restrict, suspend or cancel the InterContinental Ambassador and Royal Ambassador benefits and discontinue the Priority Club Rewards membership of any member who acts in a manner inconsistent with applicable laws, rules, regulations, or these Terms and Conditions, in SCH’s sole discretion.
13. SCH may amend the InterContinental Ambassador and Royal Ambassador benefits and these Terms and Conditions at any time



In my youth I was a lawyer. But I saw the light and escaped early. ^ Though my training was a long time ago, even I can see that any half decent lawyer could drive a truck through these badly drafted "rules". For what it is worth here is my interpretation of some of the more common issues. Real lawyers out there can probably do better than this amateur.

a. Selling or exchanging a referral certificate including on Ebay or even Coupon Connection is prohibited because you can't "transfer". Of course, enforcement of the rule is a different issue. I guess they are saying that actually referring someone is not a "transfer". It is using the certificate.

b. A bogo is only valid at an IC on the second night of a Friday/Saturday or a Saturday/Sunday stay, except in the Middle East when there is a different definition of a weekend.

c. The bogo rules do not state that you have to be in the same room type for both nights of the stay though this is the practice.

d. The bogo only officially covers room and tax. Practice is to cover breakfast/club etc access when included in the rate. Are those inclusions part of the "room" or is there inclusion really grace and favor? Promotions are excluded but promotions do not include any openly available rate. Interpret that how you want!

e. For ambassadors, a superior room, as defined by the hotel, will be asigned at check-in. There is no statement "if available". What happens if there is no room is not stated. I would expect a rate reduction but it does not state that that will occur. In fact, the rules give the hotel no alternative but to make the superior (again, as defined by the hotel) room available.

f. Late check out is not "subject to availability".

g. Most ambassador benefits can be denied on reward stays.

h. Mini-bar includes beverages only. Anything else is over and above the terms. Arguing that a downgraded mini-bar for a RA, as apparently occurs in some hotels, is a breach of the terms does not appear to be supported by the rules. The rules also do not state that the mini-bar must be refilled. Not nice, but not part of the rules.

i. For RA's the upgrade will be assigned at check-in and will be to an executive room or suite. No mention of club rooms. No mention of two level upgrades. There is no mention of what happens when the upgrade is unavailable. Indeed, the rules seem to imply that they'll put you in a regular room until one becomes free. I cannot see how any hotel can talk about upgrades "on availability". I cannot find anything which gives them the right to deny.

j. The terms also state that benefits are provided where available at the "sole discretion of IHG". They do not state that they are at the discretion of an hotel. The meaning of "IHG" is critical.

Finally, just as I now carry a copy of the rules of my frequent flyer scheme as I have one or two arguments over lounge access, I now intend to carry a copy of the terms of the Priority Club scheme.