From Dota 2 Wiki
| Soul Ring|
|A ring that feeds on the souls of those who wear it.|
- Interrupts the user's channeling spells upon cast.
- If the mana bonus would exceed the user's current mana pool, its max mana pool is temporarily increased by the exceeding amount.
- At the end of the duration, the user loses any unused mana of the 150 mana bonus.
- If its maximum mana pool was increased, it goes back to normal if it was exceeded.
- Only counts actually spent mana. Mana lost in other ways (like Nether Ward, Mana Break or Mana Burn) does not count.
- The lost health is not gained back when the gained mana was unused or partly unused.
- The 150 health lost upon cast is never lethal. When casting with less than 150 health, the user's health goes down to 1.
- If Alchemist is facing a hard lane, he can use Soul Ring to get last hits by using Acid Spray repeatedly.
- Bane can use the mana to cast more Brain Sap, which also recovers the 150 health you lose from soul ring
- When low on health, you can use soul ring to drop you to 1 health, then use Nightmare to deny yourself
- Broodmother needs Soul Ring to constantly use Spawn Spiderlings and maintain her brood.
- Soul Ring lets Dark Seer repeatedly use Ion Shell, allowing him to safely farm in lane from a distance.
- Earthshaker's low mana can be offset with Soul Ring, allowing him to use Fissure more often.
- Soul Ring lets Enigma use Demonic Conversion more often, both in the jungle and in lane.
- Soul Ring allows Ogre Magi to cast Fireblast frequently, and play more aggressively in lane.
- Omniknight's small mana pool can be boosted by Soul Ring, which is especially helpful for getting off an extra Purification.
- Soul Ring is absolutely crucial for Techies because it allows him plant many more mines, and remains useful throughout the game.
- Soul Ring helps Tinker with March of the Machines and Boots of Travel, both of which can drain Tinker's mana very quickly when used twice in conjunction with Rearm.
- Soul Ring's cooldown can also be refreshed with Rearm.
- Soul Ring helps Zeus use his magical nukes more often, and its health reduction is not as risky because of his global range with Thundergod's Wrath.
- Use Soul Ring right before casting a costly ability. This is especially effective during the laning stage, as it will offset most of your mana costs.
- Make sure you are safe before using Soul Ring, as the reduced health can make your hero much more vulnerable.
- When the cooldown goes off (30 seconds) the health regenerated is 90, i.e. 60% from the original 150 health consumed, so the value of health used for the Sacrifice ability is 60 health, only the 40% of the total used.
- If your hero has low health or no means of regenerating health, consider picking up Tranquil Boots too in order to refill health after using the active a lot.
- Consider dropping items that increase mana capacity before using Soul Ring and picking them back up afterwards. Dropping those items decreases your mana capacity while current mana percentage remains the same, but Soul Ring still gives the full amount of mana. Picking up the items afterwards increases mana capacity while retaining the same percentage, thus resulting in a net gain of mana. As an added bonus, the extra mana gained through this method does not count as having been gained through the Soul Ring, and as such, will not be lost at the end of the duration even if unused.
- Soul Ring was the only item not allowed in The International 2013 Solo Championship.