When this attacks, the top unit or weapon in your deck gets +1/+1.
When this attacks, the top unit or weapon in your deck gets +X/+X.
- Find more cards with Warcry in its category page.
Mulitple warcry effects added to the same unit will stack - for example, adding Warcry to a unit that already has Warcry will give it Warcry 2.
Warcry triggers immediately after the attack is declared, so it will trigger even if the unit is removed from play before dealing damage, or if the attack is cancelled due to the blocker being removed from play.
A deck with Warcry loves attacking as it causes the ability to trigger.
The popular Eternal website, EternalWarcry is named after this mechanic.