Do not buy them to use for decks
This terminology can be found on cards like Gloom, Verduran Enchantress, Iron Star, and Throne of Bone
That means you can use activated abilities that require a tap straight away Heartless Hidetsugu, for example, can be slammed onto the table and fire off damage equal to three-quarters of the table's life total in a single turn
Incapsula incident ID: 329000750018385233-54796730382226128
Personally, I treat individual games of Magic as instances of a longer iterated game that is all the games of Magic I will play, and I think the benefit I could get for dishonesty isnt worth the long term cost, but I know other players who would always break their word if the outcome of a game directly hinges on it, and I even still might trust some of those players in situations where I think the outcome of a game is unlikely to directly hinge on the thing were discussing
Im sure as the weeks and months drag on that Ill find a lot of other sweet hidden or forgotten cards to highlight for players going deep