During a Duel, players may not look through their Main Deck, unless allowed to do so by a card's effect
It gives all of your stuff ward: sacrifice a permanent, nice in things like Treasure-dense decks and overall powerful
During your Main Phase: You can excavate the top 3 cards from your Deck, and if you do, you can either add to your hand or Special Summon 1 excavated "Gunkan Suship Shari", also shuffle the rest into your Deck
It remains noteworthy, insofar as it's rarer than the above and a guaranteed pull in every pack
With 200+ cards to collect, newcomers to the game and seasoned players will uncover more dual-ink cards, illusions, and so much more
Knowing the first two points here, it's not as much of a surprise, but