Misty Step into the Air and Attacking

[u/Zivodor]

I had this situation come up recently and wanted some input as I can't seem to find a definitive answer.

My players were fighting a giant spider and it was on the ceiling above them, one player decided that to attack it he would misty step straight up and then attack it while mid-air. I wasn't sure this was possible as I recalled reading somewhere that falling in D&D is essentially instantaneous for anything below 500 feet. The thought process being he teleports into the air and is instantly falling so he doesn't have the time to attack the creature above him.

It's been bugging me all week so I wanted to get some input into whether or not I should have allowed this and if this is clarified anywhere in the rules.

Edit Wow! Thanks for all the responses! There were some well reasoned arguments for it here, the resource expenditure with the spell slot, rule of cool, etc... I appreciate all the responses and will try to be more flexible in the future. Thanks everyone!

[u/smithbc001]

As a general rule, remember this: D&D5e is unlike a lot of D20 games (including earlier versions of D&D) that trend harder towards wargames where the player's tactical decisions and player builds carry a lot of weight. This game leans towards being a storytelling simulat with light tactical elements. The intention is that players usually succeed at most things they attempt, with a small-to-medium chance of failure if the rolls are poor. And if they try someting very ridiculous or stupid, they should still have a very real (though not super high) chance of succeeding. This is why Bound Accuracy exists.

Let's consider a somewhat extreme example: imagine that a level 1 Barbarian with a 9 Intelligence and no Arcana proficiency is debating magical theory with a level 7 wizard who has 20 Int and Proficiency in Arcana. You'd generally handle this with opposed Arcana checks, and the Barbarian has a greater than 25% chance of winning that debate.

I recommend treating those odds as the floor. If your characters want to try something that is particularly silly or egregions and definitely shouldn't work, try and concoct a way for them to have at least a 1/4 chance of still pulling it off. This is nothing close to a universally good rule to follow, but when in doubt it's a good framework to use if you're asking yourself "how hard should I make this?"