Mana burn
Mana burn is an obsolete game concept in which a player would experience loss of life for having excess unspent mana when a phase ended.
Description
For instance, if a player tapped a Swamp to cast Dark Ritual, adding 
to their mana pool, then cast Erg Raiders (which costs 
), and then let the phase in which Erg Raiders was cast end but didn't spend the remaining , that player would lose 1 life from mana burn.
Rules
From the Comprehensive Rules (May 1, 2009—Alara Reborn)
- 300. General (Obsolete)
- 300.3. When a phase ends (but not a step), any unused mana left in a player's mana pool is lost. That player loses 1 life for each one mana lost this way. This is called mana burn. Mana burn is loss of life, not damage, so it can't be prevented or altered by effects that affect damage. This game action doesn't use the stack. (See rule 406, "Mana Abilities.")
History
The rules update to Magic 2010 has removed this part from the game.[1] Players do not suffer loss of life for unused mana anymore. R&D considered the rule too complex and unnecessary.[2]
From the glossary of the Comprehensive Rules (June 7, 2024—Modern Horizons 3)
- Mana Burn (Obsolete)
- Older versions of the rules stated that unspent mana caused a player to lose life; this was called “mana burn.” That rule no longer exists.
Design and behind-the-scenes
Mana burn was almost removed in the Sixth Edition rules update, but Mark Rosewater fought to keep it in. Ten years later, he fought to have it removed. His reasons to remove it were that it would free up design space, do away with a rule that's confusing for new players and that it's a rule that wasn't pulling its weight.[1]
He tried it out in design by having all designers play without mana burn for a month. It hadn't come up in playtests at all during the whole month.[3] The rule being relevant requires a player having significant number of mana producers that generate mana in unusual chunks or during unusual phases. Furthermore, the notion that mana burn would punish such degenerate gameplay was impractical, as single life loss is close to the cheapest payment in the game and any deck that generates life-threatening mana would only do so when they have their kill condition.
While mana burn has been a popular effect to attempt to recreate through a static ability, it took until Commander Legends where Yurlok of Scorch Thrash returned mana burn to the world of 2020.
In-world meaning
In storylines, mana burn happens when a wizard holds mana and doesn't use it to cast the spell. Such a wizard can seriously suffer from it, be killed, or even be burned to ash if the amount of mana was too big. Some victims of mana burn can also be turned into the Fallen.
References
- ↑ a b Mark Rosewater (June 22, 2009). "Magic Lessons". magicthegathering.com. Wizards of the Coast.
- ↑ Mark Rosewater (March 4, 2019). "You Know Who.". magicthegathering.com. Wizards of the Coast.
- ↑ Mark Rosewater (August 13, 2014). "why was mana burn removed from the game?". Blogatog. Tumblr.