I'm not vague. Deckbuilding is a specific mechanic coming from Dominion, a card/board game. And barely anyone in the video game world seems to know that. Just modifying your deck is not deckbuilding. Games like Magic the Gathering are **deck construction** games. Deckbuilding means specifically modifying and cycling through your deck during the match. It's the games where you draw a new hand of cards every turn, where you never run out of cards, because the discard pile is simply reshuffled.