Cards with this ability are limited to the shaman class.
- Playing a card with Overload causes the stated amount of Mana Crystals to become pending Overloaded (a padlock icon appears beneath a permanent Mana Crystal for each point of Overload) and, at the start of the player's next turn, that number of Mana Crystals will become Overloaded: the padlocks will move up and block out the player's Mana Crystals, effectively preventing them from being refilled and used for that turn.
- Overload is only charged when the card with Overload is successfully played from the hand. In particular:
- If a minion with Overload is summoned through a summon effect (such as or ) the player will not gain any Overload.
- If a spell with Overload is countered by the player will not gain any Overload, and thus their Tunnel Troggs will not trigger (however, their Unbound Elementals will still trigger since they actually played a card with Overload).
- If a spell with Overload is played by a minion or weapon (i.e. , , , etc.), you will receive Overload despite not having directly played it.
- If a Battlecry with an Overload effect is triggered twice (i.e. , , ), it will not double the number of Overloaded crystals.
- A player's current and/or pending Overloaded Mana Crystals has no upper limit.
- In particular, a player can Overload more mana than they will have the next turn: even if the user interface will only display Overload equal to the player's maximum mana, the excess will still be registered and will affect mana-generating effects like and . Once the Overload has been matched, any further mana generated will be usable by the player, and will be reflected in the mana counter.
- Example: If a player plays two Dust Devils on turn 2, the result will be an Overload of 4 mana on turn 3: despite only 3 Overload will show in the interface (since the player has only 3 maximum mana), if is used the player will still have 0 available mana, and will be unable to play 1-Cost cards.
- Example: Overloading for 10 mana on turn 9 will only display 9 pending Overloaded Mana Crystals, but at the start of turn 10 a 10th padlock icon will appear to correctly indicate that all 10 mana are Overloaded.
- Overload affects available mana only for the next turn: current Overload will disappear (regardless of its amount) at the beginning of the player's next turn, when it will be substituted by previous turn's pending Overload.
- Example: If a player plays two Dust Devils on turn two, on the next turn they will have 4 Overloaded mana despite having only 3 Mana Crystals: this mana deficit will not carry over to subsequent turns, thereby allowing the player to avoid paying that part of the Overload cost at all.
- Overload sort of "splits" the "true" cost of a card over two turns: however, you cannot avoid it even if you have sufficient mana this turn to pay the "full" cost.
- and unlock and refill all currently Overloaded Mana Crystals, increasing available mana accordingly, and clear any pending Overloaded mana.
- Cards that check for Overload like and will work with both Overloaded crystals and pending Overloaded crystals.
- Effects that destroy Mana Crystals have no effect on current and/or pending Overload, despite the visual appearance of destroying a pending Overloaded Mana Crystal.
- Overloaded and pending Overloaded mana are not displayed for the opponent directly: players trying to estimate the opponent's available mana next turn can either use the history to check the cards played that turn or hover over their opponent's Mana Tray to see how much are locked.
Overload allows shamans to deal very effective burst damage, and to summon some powerful minions in the early game. Overload adds an additional strategic element to the game, with the shaman gaining tempo and presence in the current round in exchange for restricted activity in the next.
Used unwisely, Overload can leave the shaman starved of mana the next turn, causing them to lose pace and potentially drop behind in the game. Be wary of using Overload in early rounds to summon powerful minions which can be easily removed by the opponent next turn, since the additional Overload cost can cause the shaman to pay twice over. Used wisely, Overload can allow the shaman to respond to demanding situations with surprising momentum.
An additional strategic element is added through certain Overload-related cards. Cards like and remove all Overload for the current and coming turn, allowing the shaman to free up mana and drastically reduce the overall cost of their Overload cards, especially if played after incurring a large amount of Overload. Other cards such as and offer a simpler synergy, with triggered effects activating in response to Overload. Overload decks combine cards such as these with a large amount of Overload cards, using cards like Lava Shock to reduce their cost, while using the Overload-triggered cards for additional threats.
Cards with Overload
|Sensory Overload (1/3)||Play 15 cards with Overload.||10|
|Sensory Overload (2/3)||Play 50 cards with Overload.||10|
|Sensory Overload (3/3)||Play 150 cards with Overload.||10|
- For a few weeks during Patch 220.127.116.1133 (LoE patch), playing a minion or spell with Overload caused you to become Overloaded the moment the card was paid for. For example, if countered your , you were still Overloaded (normally Counterspell triggers before Overload, preventing the effect entirely).
- During the game's alpha, Overload was known as "Recall". The name was changed in an unknown alpha patch prior to May 2013, but the keyword in the game's strings was not changed until Patch 18.104.22.16833. The change is not known to have otherwise altered any card text or the mechanics involved, but may have reflected a different concept behind the ability.
- Alpha patch (unknown date, pre-May 2013): Keyword name changed from "Recall" to "Overload".
- BuB ChaCha (2015-02-17). Overload:(10) vs. Innervate 超載:(10) vs.啟動.
- BuB ChaCha (2015-02-16). Overload: (20) =?｜超載:(20) =?.
- Tested by User:Taohinton, 2014-02-19. Tested twice: Played x 2 on turn 2. On turn 3 the mana bar showed 0/3 mana. Played and a fourth mana crystal appeared, without a padlock. However, the total remained at 0/3, and I was unable to play any 1 mana cards.
- http://us.battle.net/hearthstone/en/forum/topic/19877077551?page=1#4 Tested in Patch 22.214.171.12433 (LoE patch)
- Ben Brode on Twitter. (2015-11-16).