Q 74

An interesting question came up at my last session and I couldn't find the answer to it on my own:

We all know that when you take a readied action, your initiative count changes to just before the event that triggered your action. But what happens when multiple characters are readying for the exact same circumstance? How is the initiative order determined when everyone's initiative gets set to "just before" the triggering action?

We were fighting a wraith and it was doing the usual fly-by into and out of solid objects, never staying around outside of its own turn, so we were all readying spells and eldritch blasts and such for whenever the thing showed itself. Unfortunately, the text about readied actions is written from the perspective of a single character with no mention of multiple characters taking essentially the same readied action.