Pool of Reflection

A Pool of Reflection is a type of environmental object introduced in the pre-expansion patch of Reaper of Souls, and Diablo Immortal. It provides a bonus to earned experience. While under its effect, the experience bar will turn yellow.

Diablo Immortal
If one activates the Pool of Reflection, players receive an increased chance in spawning Experience Globes.

Diablo III
Encountered on the playing field as yellow wells, similar to Healing Wells, players interact with a Pool of Reflection via drinking from its blessed waters (by clicking on it). Upon doing so, the pool will fully heal the hero and grant an experience bonus, according to the following restrictions:


 * Each character in an account has its own "bonus pool." For example, if a player playing a Barbarian clicks on a pool, and then switches to a Demon Hunter, the Demon Hunter will not receive an XP bonus.
 * Bonus pools persist across games and game sessions.
 * Clicking on a Pool of Reflection adds 10 percent of the EXP needed for the player's current level—normal or Paragon—to that character's bonus pool. At any given time, the bonus pool is limited to the same number of EXP as the total needed to level. For example, at Paragon level 1, where 7,200,000 EXP are needed to reach Paragon level 2, each Pool of Reflection adds 720,000 EXP to the bonus pool, and the bonus pool is limited to 7,200,000 EXP; at Paragon level 500, each Pool adds 185,232,000 EXP.
 * While the bonus pool is active, all sources of EXP are increased by 25 percent (that is, multiplied by 1.25), including the bonuses for completing bounties and rifts. As this additional 25 percent is added, it is removed from the bonus pool. A diamond on the experience bar shows where the pool will end, if it ends on the current level; if it extends past the current level, the diamond will appear at the end of the bar.
 * Any death, regardless of cause, results in the complete loss of any bonus pools. Thus, it may be better for Normal characters to wait until after dealing with a mob or elites before clicking on the pool. On the other hand, Hardcore characters are lost upon death anyway, so they should probably utilize the pool immediately.