Harrah's Rincon usually has 3 or 4 multiplier days each month. The multiplier is determined by your player's level and is open to everyone with a player's card.
Sometimes they also have multiplier days that are for invited guests only.
September multiplier days are "mystery" multiplier days-there are the regular multipliers for each players level, but you may get a better multiplier.
From the Rincon website.
"The Casino at Harrah's Rincon (San Diego)
Multiply your Reward Credits up to 50X on Sept. 3, 5, 12, 17, 19, 24 & 26! Redeem them for Free Play! Swipe your Total Rewards card at the Multiplier Kiosks from 6am - 5:59am to unveil your multiplier! We're guaranteeing the following multiplier amounts:
Seven Stars cardholders:
9x on Slots and Table Games
5x on Video Poker
Diamond cardholders:
7x on Slots and Table Games
4x on Video Poker
Platinum cardholders:
5x on Slots and Table Games
3x on Video Poker
Gold cardholders:
3x on Slots and Table Games
2x on Video Poker
Reward credits will be added within (7) seven business days. See the Total Rewards Center for complete rules and details."
