Explain Hallowed Ground

[Rongway]

It gives you a 100% resistance to all damage that isn't explicitly programmed to ignore it (boss ultimate attacks after failed checks, mostly).

For best effect, you should have the buff active (on your buff bar) before the enemy's cast bar (if visible) finishes filling, not just before the moment of impact. Other jobs' shields, like Manawall or Stoneskin, absolutely must be active before the enemy finishes casting. Hallowed Ground is slightly more forgiving than those, but you should still strive for this order of events:

1. Push the button for Hallowed Ground.
2. You gain the effect of Hallowed Ground.
3. The enemies finish casting, or activate instant attacks.
4. The enemies hit you for 0 damage.

Because of this timing, Hallowed Ground, like your other cooldowns, works best when its use is premeditated. Using it as an emergency ability will usually lead to using it too late, putting the ability on cooldown without providing the protective benefits.