How do Trifarian War Camp's +1 Might buff and Thousand-Tailed Watcher's -3 Might debuff interact? Is the +1 Might snapshotted, and what happens when a unit leaves the battlefield after being affected by both effects?

Question

Accepted Answer

No — Trifarian War Camp’s +1 [M] is not snapshotted. While a unit remains at the battlefield, its current Might is the printed Might plus ongoing modifiers (e.g., Trifarian War Camp’s +1 and Thousand-Tailed Watcher’s −3) evaluated together. When the unit leaves the battlefield, battlefield effects stop applying and the unit’s Might in non-board zones is its inherent/printed Might.

Effects like Trifarian War Camp that grant continuous +1 Might are applied continuously (not snapshotted) and combine with other continuous modifiers (such as a −3 from Thousand-Tailed Watcher) to form the unit’s current Might while it is on the board. If that combined Might crosses thresholds (for example becoming 5 or greater) the unit becomes Mighty at the moment the Might changes. When the unit leaves the battlefield to a non-board zone, those battlefield effects no longer apply and the unit is evaluated by its inherent/printed Might in that zone [711]. If the resulting Might is less than 0 it is treated as 0 when referenced or when summing Might for combat purposes [143.2.b].

Determine the unit's printed/base Might, then apply all continuous on-board modifiers (for example Trifarian War Camp’s +1 and Thousand-Tailed Watcher’s −3) to get the unit’s current Might while it is on the battlefield [710]. If the unit’s current Might crosses from below 5 to 5 or greater due to those applied modifiers, it "becomes Mighty" at that moment [709]. If damage on the unit ever equals or exceeds its current Might while on board, it is Killed (and removed) using that current Might to check lethal damage [143.2.a]. If the unit's combined modifiers cause its Might to be less than 0, treat the referenced value as 0 where the rules require (such as when summing Might for combat) [143.2.b]. When the unit leaves the battlefield to a non-board zone, continuous battlefield effects (like Trifarian War Camp’s +1) no longer apply; the unit is evaluated by its inherent/printed Might in that new zone [711].

If the unit’s Might changes while on the board such that it is killed as a result of that change, use the current on-board Might (including both +1 and −3 modifiers) to determine whether its marked damage is lethal [143.2.a] [710]. If multiple separate +1 Buffs exist, each counts individually per [703]; a −3 modifier simply sums algebraically with those buffs when computing current Might [703] [710]. If the unit is moved or replayed while an effect is pending on the chain, its final zone when the effect resolves determines whether battlefield modifiers apply; non-board evaluation uses inherent Might [711].

While a unit is on the battlefield you always use its current Might, which is its printed/base Might plus any ongoing modifiers that apply while it’s on the board. Trifarian War Camp grants a continuous +1 Might to units at that Battlefield; that +1 is not snapshotted at a single moment but is part of the ongoing calculation of the unit’s current Might while it remains there [710]. Any other continuous modifier that applies on the board (for example a −3 from Thousand-Tailed Watcher, assumed here to be an on-board ongoing effect) algebraically sums with the +1 from Trifarian War Camp to produce the unit’s current Might while on the board (multiple +1 Buffs are each applied individually per [703]). If the combined on-board Might change causes the unit to cross the 5-Might threshold, it "becomes Mighty" at that moment [709]. If the unit has damage marked equal to or exceeding that current Might, it is Killed using that current Might to determine lethal damage [143.2.a]. If the algebraic result of all modifiers would make the unit's Might less than 0, that value is treated as 0 when referenced by spells and when summing Might for Combat [143.2.b]. When the unit leaves the battlefield to a non-board zone, battlefield modifiers (including Trifarian War Camp’s +1 and any on-board debuffs) stop applying and the unit is evaluated by its inherent/printed Might in that zone [711].