08 Feb Guiding Bolt 5e D&D Guide 
The bread-and-butter combat spell of the typically supporting cleric, Guiding Bolt does damage and grants allies an advantage in combat. Often overlooked, it can be one of most tactically sound spells in the game.
The rules for Guiding Bolt are found in The Players Handbook on page 248.
Guiding Bolt 5e
Evocation 1st Level
Casting Time: 1 Action
Range: 120 Feet
Components: V, S
Duration: 1 Round
A flash of light streaks toward a creature of your choice within range. Make a ranged spell attack against the target. On a hit, the target takes 4d6 radiant damage, and the next roll made against this target before the end of your next turn has advantage, thanks to the mystical dim light glittering on the target until then.
At Higher Levels: When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d6 for each slot level above 1st.
The rules for Guiding Bolt tell us a few things. The spell is meant for use in combat, it offers good damage for a 1st level spell and can be up-cast. Additionally, there is the added benefit of giving an ally a better opportunity to hit, meaning it is a quality support spell as well.
Is Guiding Bolt Good?
Guiding Bolt is a level 1 spell that does 4d6 damage, so, yes, it’s good. The fact that it can be up-cast as the character progresses means that it stays relevant throughout level advancement. The advantage granted on the next attack on the target is incredibly powerful when teamed up with a rogue’s sneak attack or a melee ally with brutal critical. The fact that it does radiant damage is icing on the cake.
There are some downsides to Guiding Bolt, though. Primarily, it is part of the cleric spell list, so using it leaves one less slot available for healing. The other issue with it is that it requires a ranged spell attack. A typical cleric will have high wisdom and possibly high strength, but dexterity is generally further down the list. Clerics are usually built around being armored to boost their armor class (AC).
There are very few spells that can match Guiding Bolt at first level and beyond. The radiant damage is great and not the most common resistance. It is a spell that can really allow a cleric to change the outcome of a fight in a single cast.
Does Guiding Bolt Need Sight?
The spell does not specify “a target that you can see” simply one that you chose within range. The rules of making attacks explain that attacks on unseen targets (via invisibility or darkness) are made at disadvantage. This does not allow you to target around corners or behind full cover. The spell still requires a direct path to the target.
Guiding Bolt might be a clerics best attempt at a knockout punch or at least setup for one. The damage output is high, so it may take a tough enemy out at the end of a fight. Another idea is that even an enemy that survives is still giving advantage to the next attack on it, providing a better chance at a critical. Using the spell at the presumed end of the fight is important because it draws away potential healing spell slots.
Guiding Bolt: Optimized for Support in Combat
It has been covered that Guiding Bolt has standalone damage output. Optimizing the spell to get the most out of it in combat makes it even better. It doesn’t make much sense to use it on low-level minion type enemies, so save those slots. Instead, focus the spell on the big bad when they show up.
Chances are that a DM is not going to present a big bad that can be one-shot with this spell. This means you are looking to play support with your spell. Look at the initiative order, so you can set up the next ally to really do some damage.
This may take some planning and strategy, but it is worth it. To get the best bang for your buck, cast the spell when you can have the paladin come in with a smite, or the rogue can unleash a sneak attack. If this is the plan, there may not be a reason to up-cast the spell since the advantage on the attack is granted at the spell’s base casting level.
The case can be made for never up-casting Guiding Bolt. Since spells can critically hit, on a natural 20, Guiding Bolt does 8d6 damage. That is equivalent to a fireball spell. Plus, the advantage benefit.
Guiding Bolt should be prepared by every class that can prepare it. The spell is an excellent combination of damage and support, a rare mix in the game. It is available as a level one spell and has no cap on up-casting levels.
It is disappointing when it is cast and misses, but when it hits, it is oh so sweet. The cleric class is one of the most versatile in the game when considering the number of different domains that are available. There is no reason to feel like just a healer anymore, and spells like Guiding Bolt really emphasize that point.