So, R&D has had lengthy discussions about Cavern of Souls. The card's templating is unique; there hasn't ever been a card before that has two invisible effects that have such different implications for the game state, and that wasn't anticipated before release. Given the problems that it causes, I suspect it'll be the last to use this template.
In the end, the original designer intent of the card was that it always applied when you cast a spell with the appropriate type, whether you had actually remembered to activate it properly or not. Because of this, they've asked us to reconsider the ruling that you need to announce Cavern of Souls if you want the spell to be counterable.
We're sympathetic to their desires and, as I said in the previous mail, there were arguments to be made for both sides, even if philosophy supported the original interpretation better. As a result, we're reversing the ruling. If a Cavern of Souls gets tapped for the appropriate creature type, the spell is uncounterable whether they say anything or not. We'd still prefer that players be clear about the game state, of course.
There'll probably be a bunch of confusion about this initially. We did a good job (I think) of getting the word out the first time around, so it'll take a while to educate everyone about the reverse. I'd strongly encourage everyone to make reminder announcements at their events for the next few. I know I will be at the start of GP:Anaheim!
Unique and messy cards are, fortunately, few and far between, and tournament-playable ones are rarer still. Apologies for the confusion, and hopefully this uses up the allocation for the next several years!
In due parole: prima, se tappavi la Grotta per giocare una creatura del tipo scelto, ma non specificavi il tipo di mana attinto (se quello incolore, o quello colorato che garantisce l'incounterabilità), la carta POTEVA essere counterizzata. Ricordo che una cosa del genere è successa anche in un recente torneo importante (se non ricordo male Finkel riuscì a fare un Mana Leak su una creatura avversaria, nonostante questa fosse stata giocata con la Grotta e fosse del tipo specificato, proprio per questo motivo). Adesso invece se una creatura del tipo scelto viene giocata con la Grotta, automaticamente la si considera giocata con il mana colorato e quindi non counterizzabile.
Personalmente preferivo com'era prima da un punto di vista di gioco (anche le attenzioni a simili particolari fanno la differenza tra giocatori davvero bravi e non), ma, da un punto di vista arbitrale, questo toglie moltissimi grattacapi e invettive contro ogni genere di santo o divinità. X-D