I feel like most tables end up asking this question and I think it usually comes down to a table by table decision, but can a caster who has been knocked prone use teleportation to stand up again? I'm seeking a RAW answer or a Crawford quote if available.
For example, a wizard is knocked prone before an ogre. In the interest of getting out of that terrible situation, they cast Misty Step to teleport anywhere else 30' away. When they arrive, do they need to use half their movement to stand to resume their escape or can they arrive standing and move at full speed?
Best Answer
The basic (but unwritten) rule is that spells do not do things that are not in their description. There is a price to pay for standing up and misty step and other similar spells do not waive it.
But there is a way around this. (Inspired by this answer.)
If you do not teleport onto the ground (and there is no such requirement in misty step), then you will obviously fall and therefore follow the rules cited above. If you do not teleport higher than 10 feet, you take no damage and therefore do not land prone, leaving the only option of on your feet. Since you do not move horizontally, you cannot teleport that far away (deducting 5 feet seems a reasonable approximation).