Complete the indicated task to unlock the corresponding decoration:

Act 1 (elevated risk) decoration: Complete act 1 under elevated risk.
Act 1 (low risk) decoration: Complete act 1 under low risk, normal risk, or elevated risk.
Act 1 (normal risk) decoration: Complete act 1 under normal risk or elevated risk.
Act 2 (elevated risk) decoration: Complete act 2 under elevated risk.
Act 2 (low risk) decoration: Complete act 2 under low risk, normal risk, or elevated risk.
Act 2 (normal risk) decoration: Complete act 2 under normal risk or elevated risk.
Act 3 (elevated risk) decoration: Complete act 3 under elevated risk.
Act 3 (low risk) decoration: Complete act 3 under low risk, normal risk, or elevated risk.
Act 3 (normal risk) decoration: Complete act 3 under normal risk or elevated risk.
Master Tutorial Challenge 1: Kill all of the enemies without getting hit.
Master Tutorial Challenge 2: Kill all the enemies with one headshot per enemy.
Master Tutorial Challenge 3: Kill the tank using only one satchel charge.
Master Tutorial Challenge 4: Have your team kill all five enemies.
Mission Accomplished Decoration: Complete all secondary objectives.
Single Player Master Decoration: Unlock all other single player decorations.
Tutorial Walkthrough Decoration: Complete the tutorial.