Abilities that allow creatures to block an additional creature are worded differently, but they don't seem to change the effect. Please help me understand why neither kind of wording is cumulative.

Coastline Chimera's activated ability allows it to block an additional creature until end of turn. Originally it can block one. After resolving the ability, it can block two. Resolve it again, and it can block three. But all of these effects end at the end of the turn. Luminous Guardian is similarly worded. These effects I understand.

Now take a look at Echo Circlet and the way its first ability is worded in Oracle. Oracle adds the words “each combat” at the end. That doesn't sound like the effect has a duration. Foriysian Brigade is similarly worded. Now, to me, this seems like the effect accumulates with each combat. So, if a player equips the circlet to a creature before combat, the ability allows the creature to block an additional creature, equaling two. On the opponent's turn, during combat, it seems that the equipped creature can block three creatures now. Then the next combat, it goes up to 4. After all, the circlet doesn't put a duration on the effect, such as “until the end of the turn”. Yet, nothing in Oracle says that the effect accumulates on itself, so I presume the effect ends at some point. But when? And why?

Edited Scott Marshall (July 11, 2016 06:23:04 PM)

Hello,

Echo Circlet has a static ability: it only has that ability as long as the Circlet is attached to the creature. It doesn't need a duration, because the duration is “as long as the Circlet is attached to that creature” (just like how Vulshock Morningstar won't continue to give the creature +2/+2 if the Morningstar becomes attached to another creature). If the Circlet stops being attached to a creature, it no longer has that ability, so its unable to block an additional creature. The Chimera and Guardian are different: they gain the ability to block an additional creature due to an activated ability resolving, and we need to define an end point for that ability, or it will last indefinitely (hence why they say “this turn”)

Nathan Long
Magic Rules NetRep