Threefold Signal
Artifact
Oracle Text
When this artifact enters, scry 3.
Each spell you cast that's exactly three colors has replicate {3}. (When you cast it, copy it for each time you paid its replicate cost. You may choose new targets for the copies. A copy of a permanent spell becomes a token.)
Watch Out
This triggers when the spell is cast, before it resolves. Even if the spell is countered, the cast trigger still resolves. Copies of spells are not cast, so they won't trigger this.
Copies don't copy counters, equipment, auras, or other external modifications. A copy of a transformed card copies only the front face. If the copy enters the battlefield, it triggers its own ETB abilities.
This card involves continuous effects applied in layer order. Type changes (layer 4) are applied before ability changes (layer 6) and P/T changes (layer 7). The order matters — a creature that loses abilities in layer 6 can still get new abilities from effects applied later in the same layer.