Challenge mode dungeons will no longer scale players down to a fixed power level.
There are no longer Bronze, Silver, and Gold timers, just one timer that is roughly the same as Silver would have been. Required kill counts still exist.
The leaderboards will focus on the highest difficulty level you have cleared, not times.
There won't be unique cosmetic items this time, but instead different Artifact appearances.
A charged Challenger's Keystone is used to start the Challenge Mode dungeon.
Keystones come from world quests.
Each player will be able to get one keystone per week. There may be opportunities to get additional ones as a bonus, but one will be the baseline.
Keystones have a power level that determines the difficulty and reward.
The higher the power level gets, the more damage the enemies do and the more health the have.
Higher level keystones will have some additional affixes. For example:
Enemies enrage at 30% health remaining, doing 100% increased damage.
Additional enemies appear in the dungeon.
Enemy corpses explode and do damage shortly after death.
The party takes constant damage over time in the dungeon.
Keystone affixes will be the same for the entire region each week, so there is no need to try and find an optimal keystone.
When you successfully clear the dungeon before the timer expires, your keystone is upgraded to the next level.
If you fail to clear the dungeon before the timer expires, your keystone is depleted.
Depleted keystones can still be used to start additional runs, but those runs won't give a loot chest at the end.
If you do beat the timer on a depleted keystone run, your keystone will be upgraded and empowered again, so you can attempt the next difficulty level for loot.
For example: if you are trying Level 6 Halls of Valor and just barely fail, you will get a Level 6 quality reward chest for your group at the end of the run, but you now have a depleted Level 6 Halls of Valor keystone. You can try again and if you manage to beat the time, you will upgrade your keystone to a fresh empowered Level 7 keystone that will give you loot.
Dungeons and Loot
The system will start slightly above Heroic Dungeon difficulty.
The difficulty of challenge mode dungeons should be able to scale endlessly.
There will be a cap on loot quality being increased from difficulty:
For example, if a Tier 20 challenge mode dungeon is very hard to complete, they may cap the loot potential there, even if there are a couple of groups that can go a little higher.
This is somewhat like how current challenge modes have a gold timer that is designed to be attainable by virtually any reasonably balanced group. Players can try for even faster times for prestige or leaderboard ranks, but there aren't any more rewards.
You get a jackpot at the end of the week with loot quality based on your best run, which will be significantly higher than loot from regular runs.
There is a possibility of getting a lucky upgrade from the regular runs, but at some point your main goal will become the weekly chest.
If you are a skilled fully Mythic geared player, you will be able to do a very high tier challenge mode dungeon and they want to give you a chance to get loot comparable to that.
Loot will be in a range of item levels, somewhat like what Mythic dungeons offer in Patch 6.2.3. While there is a chance to get items equal to the best ones from Mythic raids, that is not the default expectation.
Challenge mode dungeons complement high end raiders gameplay, not replace it.
For players who do Normal difficulty raiding, but actually prefer a smaller group setting, this could replace raiding.
Challenge mode dungeons won't be part of the random matchmaking system.
Guilds, social circles, and group finder will be where you find players.
Having an unused keystone is a desired commodity, so people will be lining up to use your Keystone on a Sunday.