I'm preparing to play a certain, popular lich and am going through possible spell combos that he would use on the players.
One in particular I want to use is Time Stop + Cloudkill + Chain Lightning (It's too bad Wall of Force is also concentration – I would love to trap them in with the Cloudkill).
Now, Cloudkill is one of those spells that seems to fall under the fuzzy ruling of delayed AoE spells, like Cloud of Daggers or Moonbeam, which have the confusing ruling of only dealing damage when the creature enters the AoE and starts its turn there.
This makes me wonder how it interacts with Time Stop, which has this stipulation:
This spell ends if one of the actions you use during this period, or any effects that you create during this period, affects a creature other than you or an object being worn or carried by someone other than you.
Emphasis mine. Because Cloudkill and like AoE spells have been ruled to not deal damage, and thus affect creatures until the start of their turn, does this mean that casting Cloudkill right atop them doesn't break the Time Stop? (at least until I cast something like Chain Lightning)
Best Answer
Casting cloudkill doesn't break time stop.
Time stop doesn't break when you do something that affects a creature; it breaks when something you do affects a creature. The active verb is "affects". It breaks at the time the creature is affected, not before.
(Besides which, we don't know that the creature is going to be affected until it happens. What if you cast a spell that requires a save, and they make their save?)
The logic of the delayed-AoE spells like cloudkill is that the creature gets hit once on each of its turns that it spends any time inside the AoE. Until time stop breaks, the amount of time the creature has been in the cloud is zero, because time is stopped.