There are a number of instanced encounters within DC Universe Online that have 'loot lockout' timers associated with them. A loot lockout is applied once a character goes through and successfully completes for the 'first time' during a lockout period. (for PVP encounters, successful completion is a win) While the lockout is in place, the character can participate in the encounters again, but will not qualify for certain types of loot or rewards.

There are currently two lockout windows: the first is a 24 hour lockout, and expires/resets at 12:00AM Pacific each day. The second is a 7 day lockout - this resets each Thursday morning at 12:00AM Pacific time.

The following encounters have loot lockout timers associated with them:

Alerts (24 hours)
Raids (7 days)
Arena PVP (24 hours)
Legends PVP (7 days)
Duos (24 hours)
DLC 8 Bounties (7 days)

Each of these encounters can have their loot lockout timers removed by using Replay Badges. There is currently no limit to the number of times a lockout timer can be reset with the use of Replay Badges. These badges can be purchased from the in-game Marketplace (PC / Daybreak Cash) or from Skeet's Emporium. (PS3 / Loyalty Points) These are also granted monthly to Legendary players with a recurring membership.