When you check in to any Caesars Entertainment property* in Las Vegas, you will get a coupon sheet. The sheet has 2 coupons for every Caesars Entertainment property in Las Vegas EXCEPT the property you are staying at. At first, this seems a little odd, but it is just a ploy to get you to visit their other properties.
The coupons are usually dining and entertainment oriented, but the current sheet includes entry into a slot tournament at the Imperial Palace (now the LINQ Hotel) and $5 in Reel Rewards (Free slot play). A few that are fairly consistent are the Eiffel Tower 2-for-1 and the various buffet discounts. The picture below shows the current offers received when checking in at Planet Hollywood.
Coupons tend to be good for 4 month blocks. On my recent trip to Planet Hollywood, the coupons were good for May 1 – August 31. Earlier this year I received coupons good for January 1 – April 30.