The chest at the end of the run guarantees the GROUP two pieces of loot from the dungeon loot table. If you beat the timer you will be awarded one extra piece of loot.

In addition, roughly every 5 difficulty levels past 10 will award you with an additional piece of loot (after 10 it's an additive 40% chance per key level for extra loot). +11 has a 40% chance of dropping one extra item, +13 has a 100% chance to drop an extra item (with a 20% chance to drop another extra item) and +15 has a guaranteed chance to drop two extra items for five items total from the chest.

At the start of a week (after raid/mythic reset) a chest will appear in your Battle for Azeroth city awarding one piece of loot. It will also contain Azerite (aka Battle for Azeroth artifact power) and Titan Residuum, a new currency used to buy targeted Azerite armor. More on that below. The loot item lvl is determined by the highest level keystone run COMPLETED the previous week, within the timer or not.

In addition, the chest will also have a downgraded keystone based on the highest level keystone run completed in the season, degrading by 1 level every week you don't complete a run higher than your previous highest.

Example: You complete a +11 one week and it is your highest completed run. Next week you get a +10 keystone from your chest. That same week you don't complete anything higher than a +10. Next reset you get a +9 key from the chest.

*It will be most beneficial to complete a +15 every week to get the highest gear value from your weekly chest.