Many times this would have saved my group on our rolls.

I'm definitely saving this in my Book of Shadows. It's like Inspiration from a bard, but specifically for skill checks. And unlimited, and touch range, but yeah. XD

Tip 1: Remember that using this will drop Concentration on any other spell you have going.

Tip 2: Remember that this has to be cast in advance of an action, not as a reaction on another's combat turn.

Tip 3: Remember that you can't add this after the d20 is rolled (when you notice that the result is not quite enough).

Quote from UglyIvanhoe >>

Tip 1: Remember that using this will drop Concentration on any other spell you have going.

Tip 2: Remember that this has to be cast in advance of an action, not as a reaction on another's combat turn.

Tip 3: Remember that you can't add this after the d20 is rolled (when you notice that the result is not quite enough).

  Regarding your Tip 3: It can roll the die before or after making the ability check. So you can decide to make the roll after you have rolled your Ability Check. You are correct, however, in saying you can't decide to cast Guidance after someone has already made their roll. So if you make an Ability check and fail, casting Guidance will only work for your next Ability Check.

Tip #2 is one of most forgotten parts of this spell especially when doing something with a time limit. "I want to check this out. I cast guidance" sorry bud two rounds gone. 

Another is when the cleric tries to do it. As a reaction to what the character is about to do. Not so much an issue out of combat other than making sure you're next to the character.

Tip #4: Remember to read the spell description carefully before writing Tip #3. ; )

 Quote from Griz_Behr >>

 Regarding your Tip 3: It can roll the die before or after making the ability check. So you can decide to make the roll after you have rolled your Ability Check. You are correct, however, in saying you can't decide to cast Guidance after someone has already made their roll. So if you make an Ability check and fail, casting Guidance will only work for your next Ability Check.

 Yes, this is what I had meant: you can't add "Guidance" after biffing a roll. Sorry for being unclear with my pronouns.

If you already have the spell on you, then of course you can add the d4 after the d20. But I was addressing the common problem of seeing a poor roll and thinking "can I cast Guidance and make it better?" or the more-common "can we say I had cast Guidance before that roll?" or the most-common "Crap! I meant to cast Guidance before that!" just as the d20 hits the table.

So can you use guidance when the DM says, "you can roll for a perception check" for example, or it needs to be done before that ever happens?

> Available For: CLERIC DRUID ARTIFICER

Awww, I wanted my Wizard (a scholar with a PhW in Theoretical Magicks) to carry this one.

If I write in his background that he used to be a guidance counselor at the Academia, would that be enough explanation for him to have this (without multiclassing)?

if i have advantage can i roll the d4 twice.

OK so this has come up as a question.  It says ability check.  Does this affect general ability checks or just skill checks?

This saved my Kobold from dying.

AND DID WE CARE? Nope.

Remember that this has no effect on saves or attacks.

Quote from Ruair_Kendall >>

if i have advantage can i roll the d4 twice.

I'd say no, your roll the d20 with advantage and then add the d4 if you think you'll still need it

Casting word is:

Auspisicus Controlus

Can you cast this on yourself?

Yes.

PHB pg 201: Targeting Yourself

If a spell targets a creature of your choice, you can choose yourself, unless the creature must be hostile or specifically a creature other than you.

Quote from Johnreidsays >>

PHB pg 201: Targeting Yourself

If a spell targets a creature of your choice, you can choose yourself, unless the creature must be hostile or specifically a creature other than you.

 To further specify for folks in the future, page 201 is the beginning of the pertinent chapter, but the rule itself is found bottom of page 204.

Getting spells outside your class is a question for your DM

Quote from Ruair_Kendall >>

if i have advantage can i roll the d4 twice.

 RAW advantage is "roll a second d20"