If you play Thousand-Tailed Watcher and a unit is at Trifarian Warcamp, does it lose the +1 it has or does it go to 0 and then get +1 from the battlefield? For example, Scuttle is there with +1 from BF. Does it stay at 1?

When you play Thousand-Tailed Watcher while an enemy unit is at Trifarian War Camp, the unit's final Might is determined by the snapshotted interaction of these modifiers.

Ruling

The unit's Might is snapshotted upon the resolution of the Watcher's ability. Per Core Rule 472.3.d.2.b and FAQ #5581, if a unit has a modifier (such as Trifarian War Camp) that affects its Might, and a reduction effect (such as Thousand-Tailed Watcher) applies a minimum value constraint, that limitation is snapshotted for the duration of the effect.

For a 1 Might unit (e.g., Scuttle) at Trifarian War Camp:

1. Start: 1 (base) + 1 (War Camp) = 2 Might.
2. Watcher Resolution: The -3 Might reduction is applied to the 2 Might total, but is limited by the minimum-1-Might rule. This results in a snapshotted reduction of -1. The unit is set to 1 Might for the duration of the Watcher's effect.

Interaction if the unit moves

Because the effect is snapshotted at the moment of resolution, the unit's Might remains fixed based on the state of the board at that time:

1. The reduction value of -1 is locked in when the Watcher's ability resolves.
2. If the unit moves away from the Trifarian War Camp, it loses the +1 Might bonus.
3. Result: The unit's Might is recalculated based on its new base Might minus the snapshotted reduction. A 1-base Might unit moving off the War Camp results in 0 Might (1 base - 1 snapshotted reduction).

Clarification on Conflicting FAQs

There is documented community confusion regarding this interaction. Per FAQs #9195 and #1431, Thousand-Tailed Watcher's effect is snapshotted and sets a fixed Might value, rather than applying as a continuous modifier.

Note: There is significant documented conflict between community interpretations and official FAQs #9195, #1431, and #5581 regarding whether these effects are continuous or snapshotted. This ruling follows the guidance that these effects are snapshotted.