When a card effect reads the Damage Step does it mean that wears off afterwards in Yu-Gi-Oh?

You're on the right track, but it's not quite "wears off" - it's more about when the effect is active.

Here's how it works in Yu-Gi-Oh!:

* "During the Damage Step" means the effect only applies within the Damage Step of the current turn.

* Once the Damage Step is over (the damage is calculated, and any damage is applied), the effect stops working for the rest of that turn.

Example:

Let's say a card has the effect: "During the Damage Step, this card gains 500 ATK."

1. Your monster attacks the opponent's monster.

2. The Damage Step begins.

3. The card's effect activates, and it gains 500 ATK.

4. Damage is calculated and applied.

5. The Damage Step ends.

6. The card loses the 500 ATK boost for the rest of the turn.

Important Note: If a card has an effect that activates "at the start of the Damage Step", it will remain active throughout the entire Damage Step. This is different from effects that activate "during the Damage Step".

Let me know if you have any other card effect questions!