Way back when, many abilities which did no damage immediately would do 1 true damage so someone could be probably accredited with an assist if the target died after being hit by it.

For example, Trundle and Anivia pillar, and I think Zilean Q (during the countdown) as well.

Caenen_

Close but assist timers were just as easy to do manual as a hit effect, and damage was more useful to trigger things such as turret aggro which those spells then did.

But that didn't need 1 true damage, these terrain-creating spells were instead made to deal 0 true damage proc. Because of that, the damage proc was never visible in text (only >0 damage is displayed) and thus obscure and unknown by most players.

What was visible and actual true damage were some counters like Fizz R and Zilean Q for a while, even though Sion W already did the same thing without damage many releases prior. Heh.

welp I guess I fell prey to community rumours T_T