Hi, I am a Gurps Girl, so unfamiliar with D&D 5E.

I was hoping someone could help me...

Suppose a 12th level Cleric is trying to "turn" or preferably "destroy" a mob of a dozen Wights that are charging within spell range.

Would someone handhold me through how a D&D 5E DM would handle this, rules-wise?

Thank you!

Aren't the rules in the power's description? Based on what I recall from seeing it used in videos of people playing this edition, I think the target(s) have to make some kind of saving throw, and are then either Turned or insta-killed depending on their level relative to that of the caster. If they're Turned, as far as I can remember they then have to spend their entire movement getting as far from the caster as possible, can't willingly move closer or attack them, and have to keep saying to try and throw off the effect. I seem to recall it ends early if the target is attacked in the meantime.

Thank you Ameena. I was hoping a D&D 5E expert could just dumb it down for me so even a nitwit can understand.

I *think* the confusing part here is that it's a two-parter.

The two main components here are:

1) The ability to Turn Undead (a subset of the Channel Divinity feature, gained at level 2)
and
2) The ability to Destroy Undead as a consequence of the Turn Attempt (gained and improved at levels: 5, 8, and 11.)

So, your 12th level cleric example is facing off against some undead.

As an action, you present your holy symbol and speak a prayer censuring the undead. Each undead that can see or hear you within 30 feet of you must make a Wisdom saving throw. If the creature fails its saving throw, it is turned for 1 minute or until it takes any damage.

Steps:

1) It needs to be your turn.
2) You use your ACTION.
3) You must have Holy Symbol in hand.
4) You must present (make visible and obvious your connection to the deity/your use of the channel feature) the holy symbol
5) It also has a verbal component.
6) ALL Undead that meet the following criteria are hereby affected:
- are capable of perceiving via: Sight and/or Sound
- are within 30 feet.
7) Each affected Undead (barring other abilities) makes a Saving Throw vs Wisdom, at a DC equal to your base Spell Save DC.
8) Those that pass the saving throw: that Undead is not further affected.  Stop.
9) For those that fail the saving throw, check that Undead's CR.  If it's CR is:
- Less than or equal to the CR value indicated on the "Destroy Undead" table (so CR 2 or less), it is outright destroyed.
- Greater than the CR value indicated on the "Destroy Undead" table: It is turned and following those rules (unable to react, must walk/dash away from you as best it can.)

Gamerhandle, you are a gentleman and a scholar and I really appreciate your help!

:)

Aww, thank you!

I hope that answers the question(s?) in totality.  I spend faaaarrrrr too much time putting RPG things into Code, and if you think you need things "Broken down", try telling a box of 1s and 0s how Turn Undead works.  Now, THAT's arduous.

well, sometimes in order to eat the sausage, we have to watch it being made!  Thank you so much for all your help.