Area of effect - 5e how to turn it on in maps?

[Myrdin Potter]

I am DMing Lost Mine of Phandelver and I cannot figure out how to turn on the grid for the maps so that area of effect spells target properly.

Is there an easy explanation for this?

[damned]

Im pretty sure all the players maps have grids already turned on?
What is the issue you are having exactly?

[Myrdin Potter]

Then what are the mechanics to use an area of effect spell? Because we cannot figure it out. Only one creature gets effected by sleep, for example or any other area of effect spell.

[damned]

AFAIK there is no mechanical way to do sleep automatically. you roll the HD and determine which creatures are affected. for AoE spells that do samage or healing or buffing etc you need to target each critter in the AoE - at least thats how I do it....

[markonweb]

It seems there's a way to do AoE based on what I saw in one of the wiki tutorial videos (start watching at 2:08 until 3:01) that demonstrated overlaying the grid to apply the scale and then demonstrated dragging a cone shape out to show the area that would be impacted https://www.youtube.com/watch?v=HtFgUrLeYu4
A second video https://www.youtube.com/watch?v=wP7oeHO-nQs (from 4:28-5:50) demonstrates using the technique for a fireball. Shape of a circle 20' diameter, move it around to see what might be on the AoE and then target, drag cursor from top right to bottom left of impacted targets (multi-select) and then cast fireball. It would be great if the shape of the AoE spell and target selection could be combined but the two step process seems to cover the need. (maybe not for sleep... I haven't tried that method for sleep)

[Trenloe]

It's a two step process as mentioned by markontheweb - use the relevant pointer to draw the AoE on the map: https://www.fantasygrounds.com/wiki/index.php/Images#Pointers Then manually target all of those that will be effected and trigger the spell effect.

Sleep is different as it effects a certain HP of creatures - you need to handle this manually.