Say you are confident an enemy might cast cloudkill on their turn. Your turn is before theirs. If you ready an action to move, would that allow you to avoid getting hit by the spell?
1\$\begingroup\$ Does this answer your question: "Can you escape from the Web or Moonbeam spells using readied movement?" \$\endgroup\$– Exempt-MedicJan 31, 2020 at 3:45
\$\begingroup\$ yeah, the moonbeam part does, but Ryan's answer is more to the point. \$\endgroup\$– Amethyst WizardJan 31, 2020 at 3:48
\$\begingroup\$ Out of curiosity, how do you know it's coming? \$\endgroup\$– NautArch is on strikeJan 31, 2020 at 12:41
\$\begingroup\$ Two Mezzoloth are near death, each have 1/day cloudkill. \$\endgroup\$– Amethyst WizardJan 31, 2020 at 17:26
Yes, you can easily do this with a readied move
The damage from Cloudkill uses the standard "area damage over time" language:
When a creature enters the spell's area for the first time on a turn or starts its turn there
Just ready a move with a trigger of "when I am in the area of a Cloudkill spell". As soon as the spell is released and the cloud appears over you, your readied move triggers and you move out of the spell's area. It's well established that having a spell's area placed on you doesn't count as entering that area, and you leave the spell's area on the caster's turn, before your turn starts, so none of the conditions for damage are ever triggered, and you emerge unscathed. Narratively, you can describe this as using your readied move to dive out of the way just in time to avoid the cloud.
Minor terminology quibble: There is no "move action" in 5e. Instead, you ready yourself to move up to your speed as a reaction.
\$\begingroup\$ Comments are not for extended discussion; this conversation has been moved to chat. \$\endgroup\$– V2Blast ♦Feb 1, 2020 at 8:21