If you’ve played
That exact question was addressed in an Ask Riot post when a player noticed the key and questioned what it might be used for. Champion concept artist Riot Kindlejack had this to say about the key:
“When designing Zoe, we tried to communicate that she travels all over—not just within Runeterra but to whatever lies beyond. We also wanted to show that she’s so powerful that what might be considered an incredibly rare and wondrous item to your average Joe Valoran is a mere curio for her. This Moon Stone? Oh, it just sparkles nicely. One of Bard’s chimes? It makes a great sound! The key Zoe carries around was actually ‘borrowed’ from another champion; you’ll notice it’s missing from his updated splash art.”
So which champion did Zoe steal the key from? In order to find that out, you’d have to look at champions that had their main splash arts updated and compare the before and after versions, something that could end up taking quite a while. Fortunately, some players already had an idea of where to start, and it was quickly determined that Fiddlesticks was the champion in question who lost his key. As seen in a Reddit thread that contains both splash arts, Fiddle’s previous artwork had a key around his neck while it’s absent from the new one.
There’s still the question of what that key opens though, but that question might be a bit tougher to answer.
“As to what it opens?” Riot Kindlejack asked. “Probably best we never find out…”