Playing guidelines; predetermined actions that shills are required to take in certain circumstances.
ADDITIONAL INFORMATION: Shill rules can either be strict requirements about a shill's play or they can be a set of recommendations that allow the shill to deviate slightly for the purposes of limiting recognizable patterns.
EXAMPLE: "Since any cardroom that actually uses shills would want to hide that fact, it is difficult to say whether there are any cardrooms that really use strict shill rules. If I found one and figured out the rules, though, I think I'd make such a killing I'd never want to play anywhere else."
APPLIES TO: Online and Land-based Venues