Specifically for Bellagio - from the article -
":Their real value, however, was zero. Thanks to RFID tags embedded inside them, the chips with denominations of $100 to $25,000
could be immediately deactivated rendering them unredeemable for cash value. "
I would assume that many casinos do not make full use of RFID chip possibilities - the accompanying systems, software, training, etc must be pricey.
Also - from http://www.techrepublic.com/article/...n-rfid/5569243
"Eye in the sky
The technology could also help casinos catch card players who sneak extra betting chips onto the table after hands are dealt or players who count cards. That's one reason the Hard Rock Hotel and Casino in Las Vegas plans to switch on a new set of RFID-equipped betting chips and tables next month.
The casino is installing RFID readers and PCs at game tables. With antennas placed under each player's place at the table, dealers can take a quick inventory of chips that have been wagered at the push of a button. The PCs display all the initial bets, deterring players from sneaking extra chips into their pile after hands are dealt."