There are many threads every double XP weekend and to aid those that don't know here is the skinny...

Double XP - How it Stacks

There are presently three ways to get your XP modified in a round.

(1 Developer Applied) Double XP from the developer (mostly weekends when map packs come out)

(2 User Applied) These items are additive with respect to the duration.

      a. Prestige Coin 2x XP (Obtained by prestiging - 2 hrs per coin)

      b. Clan 2x XP (obtained by clan level unlocks on Elite - time variable)

(3 Game Applied) MOAB bonus ( 2x XP for the round)

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For the example -

(2a)1 prestiege coin is used for 2x XP (2 hrs)

(2b) clan level 30 uses its bonus 2x XP (6 hrs)

While (1, 2a, & 2b) are active..

You would be getting 4x XP for 8 hours of game time.

Add a moab you would get 8x XP for THAT round only.

As you can see you can get some large XP with these modifiers active. This brings me to the second issue that gets posted during this time.

NEGATIVE ROUND XP POSTED ON ELITE

As it stands now Elite is not able to display scores in a given round above 30,000 XP correctly.

NOTE! THE TRUE SCORE IS RECORDED TO YOUR TOTAL CORRECTLY it is just not displayed correctly. Usually it will post a negative score for that round which most likely is not the negative of the score you received. Again this is an Elite display error only.

You did not loose XP

You did not get deranked.

Only that rounds reporting is messed up.

The next round will infact have added that rounds XP and the correct XP from the previous round.

I hope this helps those confused at these stressful times

NOTE this info is direct from the developer via phone conversation.

Message was edited by: tallowby

There is one caveat - There is an unofficial max XP cap per round which is suspected to be above 60,000 XP. If this cap is reached it is said you will receive no XP or severely reduced XP. The theory is if you got that much XP you are cheating even though it is very easy to get scores this high without cheating. If you fall into this you need to contact ATVI for the fix.