Hedron-Field Purists — ruling 1

The abilities a leveler grants to itself don’t overwrite any other abilities it may have. In particular, they don’t overwrite the creature’s level up ability; it always has that.

Hedron-Field Purists — ruling 2

Effects that set a leveler’s power or toughness to a specific value, including the effects from a level symbol’s ability, apply in timestamp order. The timestamp of each level symbol’s ability is the same as the timestamp of the leveler itself, regardless of when the most recent level counter was put on it.

Hedron-Field Purists — ruling 3

Effects that modify a leveler’s power or toughness, such as the effects of Giant Growth or Glorious Anthem, will apply to it no matter when they started to take effect. The same is true for counters that change the creature’s power or toughness (such as +1/+1 counters) and effects that switch its power and toughness.

Hedron-Field Purists — ruling 4

If another creature becomes a copy of a leveler, all of the leveler’s printed abilities — including those represented by level symbols — are copied. The current characteristics of the leveler, and the number of level counters on it, are not. The abilities, power, and toughness of the copy will be determined based on how many level counters are on the copy.

Hedron-Field Purists — ruling 5

A creature’s level is based on how many level counters it has on it, not how many times its level up ability has been activated or has resolved. If a leveler gets level counters due to some other effect (such as Clockspinning) or loses level counters for some reason (such as Vampire Hexmage), its level is changed accordingly.

Hedron-Field Purists — ruling 6

The prevention effects prevent 1 or 2 damage, as applicable, from each source (regardless of who controls it) each time that source would deal damage to you or a creature you control. They prevent damage of any kind, not just combat damage.

Hedron-Field Purists — ruling 7

Remember that Hedron-Field Purists never has both of these prevention effects at the same time.

Hedron-Field Purists — ruling 8

If a source would deal damage to multiple applicable recipients, the prevention effects apply to each of those recipients separately. For example, if Hedron-Field Purists is level 1 and you cast Earthquake (“Earthquake deals X damage to each creature without flying and each player”) with X equal to 3, that Earthquake will deal 2 damage to you, 2 damage to each creature without flying you control, 3 damage to each other player, and 3 damage to each creature without flying other players control.

Hedron-Field Purists : règles, fonctionnement et interactions (MTG)

Hedron-Field Purists is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Level up (: Put a level counter on this. Level up only as a sorcery.) LEVEL 1-4 1/4 If a source would deal damage to you or a creature you control, prevent 1 of that damage. LEVEL 5+ 2/5 If a source would deal damage to you or a creature you control, prevent 2 of that damage.

How it works : Hedron-Field Purists

Original English text — Wizards of the Coast / Scryfall

#1June 15, 2010· Wizards of the Coast
The abilities a leveler grants to itself don’t overwrite any other abilities it may have. In particular, they don’t overwrite the creature’s level up ability; it always has that.
No other card is named in this ruling.
#2June 15, 2010· Wizards of the Coast
Effects that set a leveler’s power or toughness to a specific value, including the effects from a level symbol’s ability, apply in timestamp order. The timestamp of each level symbol’s ability is the same as the timestamp of the leveler itself, regardless of when the most recent level counter was put on it.
No other card is named in this ruling.
#3June 15, 2010· Wizards of the Coast
Effects that modify a leveler’s power or toughness, such as the effects of Giant Growth or Glorious Anthem, will apply to it no matter when they started to take effect. The same is true for counters that change the creature’s power or toughness (such as +1/+1 counters) and effects that switch its power and toughness.
No other card is named in this ruling.
#4June 15, 2010· Wizards of the Coast
If another creature becomes a copy of a leveler, all of the leveler’s printed abilities — including those represented by level symbols — are copied. The current characteristics of the leveler, and the number of level counters on it, are not. The abilities, power, and toughness of the copy will be determined based on how many level counters are on the copy.
No other card is named in this ruling.
#5June 15, 2010· Wizards of the Coast
A creature’s level is based on how many level counters it has on it, not how many times its level up ability has been activated or has resolved. If a leveler gets level counters due to some other effect (such as Clockspinning) or loses level counters for some reason (such as Vampire Hexmage), its level is changed accordingly.
No other card is named in this ruling.
#6June 15, 2010· Wizards of the Coast
The prevention effects prevent 1 or 2 damage, as applicable, from each source (regardless of who controls it) each time that source would deal damage to you or a creature you control. They prevent damage of any kind, not just combat damage.
No other card is named in this ruling.
#7June 15, 2010· Wizards of the Coast
Remember that Hedron-Field Purists never has both of these prevention effects at the same time.
No other card is named in this ruling.
#8June 15, 2010· Wizards of the Coast
If a source would deal damage to multiple applicable recipients, the prevention effects apply to each of those recipients separately. For example, if Hedron-Field Purists is level 1 and you cast Earthquake (“Earthquake deals X damage to each creature without flying and each player”) with X equal to 3, that Earthquake will deal 2 damage to you, 2 damage to each creature without flying you control, 3 damage to each other player, and 3 damage to each creature without flying other players control.
No other card is named in this ruling.
#9June 15, 2010· Wizards of the Coast
The prevention effects don’t affect damage dealt directly to a planeswalker you control.
No other card is named in this ruling.
#10June 15, 2010· Wizards of the Coast
The effects from multiple Hedron-Field Purists are cumulative.
No other card is named in this ruling.