En Masse is running a new "Instance Gratification" promotion for TERA over the next two weekends. The game's official website says that the goal is community building. Given the recent server merges and the upheaval generally associated with such, we think that's probably a solid idea.
If you're level 59 or under, you'll get 50% more loot drops than normal when you group up and tackle the game's dungeon content. Players of all levels get an instance reset scroll every day as long as they log in.
The bonus weekends run from September 21st through the 24th and September 28th through October 1st.