We have had some wiggle room in our stance regarding proxies, playtest cards, commemorative cards, etc.
Starting with The Brothers' War we are updating this rule very clearly and outlining the consequences of failing to adhere to this policy.
For any event we utilize the eventlink reporting system for, only legal official playable cards are allowed. Not printed paper, not gold border, not 30th anniversary, no fake cards period. Not if you have it on order, not if you have it in a different deck, not if you have it in a safe, not if you have it in a binder, not if your uncles nephews grandpappy on your mother's side twice removed is holding onto it for you. Zero Tolerance means Zero Tolerance.
Playtesting cards can be done outside of our normal events. But during any official event, including Friday Night Magic, the entirety of your deck must be official tournament legal cards.
If you are caught using non tournament legal cards during any sanctioned event you will be issued a warning and will be removed from the event. If you are caught a second time you will receive a 60 day ban from Curiosity, if you return and are caught a 3rd time you will receive a lifetime ban.