The Pool of Reflection (generally called "PoR" or "Pool") is a yellow-colored health shrine that grants a 25% buff to experience gain that lasts for some set amount of experience, or until a character dies. This feature was added to Diablo III in version 2.0.1 in February 2014, and is also present in Reaper of Souls.
The bonus from the Pool does not get added and multiplied in with other experience bonuses, but instead works to modify the gross experience gained by .25. If a character gains 100 million exp, the Pool would add 25 million on top of that, over the duration of the bonus.
Each Pool bonus adds 25% bonus experience on top of all other exp gained for some discrete amount of EXP. The bonus can stack up to ten times, potentially lasting 3-4 level ups, even if not refreshed during that time. Since characters require much more experience to advance at higher levels, the bonus exp per Pool increases with character level and with each Paragon level once a character reaches the max level.
Contents
Bonus Experience Amount
Each Pool boosts the EXP gain for about 2/5 of a level up, or approximately 4 bars of the 10 in the belt interface display. When a Pool bonus is in effect a dot appears on the exp bar showing how much further the bonus will last.
A player can stack up to 10 bonuses from Pools, which is enough to last for the next 3-4 level ups. Additional Pools added before the bonus is depleted will stack on, but never exceed the maximum of 10 stacked bonus. As a result high level characters who are not dying (such as in Hardcore) wind up with essentially a permanent Pool bonus, since it's virtually impossible to play gain that much experience without encountering more Pools in the process.
Since higher level characters require much more experience to advance a level, a single Pool of Reflection can spread its bonus for tens of millions of experience for a character on an account with high Paragon Levels. At the same time, a Pool used by a low level character will last a very short time, sometimes a minute or less if the character is killing quickly and using other +experience gear.
Tooltip Information
The tooltip is confusing, though the little dot on the experience bar is clear enough for a visual indicator.
The displayed text is oddly-presented. The bonus number refers to how much extra experience on top of the normal amount the pool is providing. As you can see in the example above, this character (from the Reaper of Souls beta) has just started gaining towards Paragon 134.
The full bar requires about 200m exp, and the dot showing the end of the Pool of Reflection bonus is about 8 bars along the 10 bar display. That's roughly 160m experience, thus the 32m bonus is 25% added on top of the experience gained. Thus 4 x 32m = 128m + 32m (pool bonus) = 160m.
Thus players who want to figure how much total exp the can gain before the Pool bonus ends should multiply the "Bonus Pool Remaining" number by 5 to figure how much experience they can gain before exhausting the Pool bonus.
Yes, confusing and weird in display. Fortunately the dot on the experience bar is simple and visual.
Sharing in Multiplayer
Pools of Reflection share their bonus equally to all players in the party, providing they are close enough to the pool when it is activated to partake in the bonus. The distance, according to Blizzard, is around 100 yards, which is a bit more than the visible screen (varies by a player's resolution settings).
During the initial testing on the PTR the Pools had a much smaller radius of shared effect, and players were required to gather very close to the pool in order to gain the bonus. Blizzard addressed this issue in patches and by the time D3v2 went live the radius of sharing was enlarged to work just like the Shrine bonuses.[1]
We’re looking to increase the range that party members receive the Pool of Reflection bonus (currently, we’re thinking that we’ll have them mirror the same radius that shrines use). We’re also planning to update the mini-map icon so that you can tell when a Pool of Reflection well is depleted. We don't have a time frame for this change at the moment and the exact details are still subject to iteration, but we’ll be sure to keep the community updated.
Helpful players sometimes call out Pools in the clan chat or to their friends, then wait a moment for others to join and share in the pool benefit when activated.
Media
<gallery> File:Pool-of-reflection2.jpg|Tower of the Damned. File:Pool-of-reflection3.jpg|Fields of Slaughter. File:Pool-of-reflection4.jpg|Rakkis Crossing. <gallery>