D&Dtools1

As you complete this spell, a shield crafted from divine energy appears before you.
As you channel energy into the shield, it grows stronger and stronger.
This spell improves your defenses.
Themagnitude of this improvement depends on the amount of time you spend casting the spell.
If you cast this spell as a swift action, you gain damage reduction 2/evil for the duration of this spell.
If you cast this spell as a standard action, you gain damage reduction 5/evil.
If you cast this spell as a full-round action, you gain damage reduction 8/evil.
If you spend 2 rounds casting this spell, you gain damage reduction 10/evil.
The spell's duration does not begin until you finish casting the spell.
You do not need to declare ahead of time how long you want to spend casting the spell.
When you begin casting this spell, you decide that you are finished casting after the appropriate time has passed.