Calculating the effectiveness of chromatic orb in D&D 2024 (5.5e)

Could chromatic orb be one of the biggest winners of the rules revision?

How has chromatic orb changed with D&D 2024?

Let’s start by looking at the rules for the spell. Up first is the 2014 version of chromatic orb:

1st-level evocation

Casting Time: 1 action
Range: 90 feet
Components: V, S, M (a diamond worth at least 50 gp)
Duration: Instantaneous

You hurl a 4-inch-diameter sphere of energy at a creature that you can see within range. You choose acid, cold, fire, lightning, poison, or thunder for the type of orb you create, and then make a ranged spell attack against the target. If the attack hits, the creature takes 3d8 damage of the type you chose.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st.

PHB 2014, p221

And now the 2024 version of the spell:

1st-level evocation

Casting Time: 1 action
Range: 90 feet
Components: V, S, M (a diamond worth at least 50 gp)
Duration: Instantaneous

You hurl an orb of energy at a target within range. Choose Acid, Cold, Fire, Lightning, Poison, or Thunder for the type of orb you create, and then make a ranged spell attack against the target. On a hit, the target takes 3d8 damage of the chosen type.

If you roll the same number on two or more of the d8s, the orb leaps to a different target of your choice within 30 feet of the target. Make an attack roll against the new target, and make a new damage roll. The orb can’t leap again unless you cast the spell with a level 2+ spell slot.

Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 1. The orb can leap a maximum number of times equal to the level of the slot expended, and a creature can be targeted only once by each casting of this spell.

PHB 2024, p249

Most of the spell remains the same, from the damage, damage types available, range and so on. But there’s one important change. Now, when rolling for damage, if you roll 2 of the same number, then you can allow the orb to bounce to another target causing them to be damaged by the spell as well.

While this feels proportionate in how damage can scale with a lucky roll, this becomes increasingly powerful when you upcast chromatic orb with a higher spell slot. When this happens, the number of d8s rolled increases by one for each level upcast by, as does the number of potential bounces.

Eagle-eyed mathematicians may notice something here. The more d8s rolled, the higher the chances of rolling a double and causing an extra target to be struck. But just how likely is that to happen, and how devastating could it be?

Calculating chromatic orb’s probabilities

This is where all the mathematics comes into play. Let’s start with the chances of having the orb bounce each time it hits at each level. Credit goes to D&D Beyond user Sillvva for calculating this one. I’ve also included average damage if all bounces hit:

Level	Potential number of targets	Chances of bouncing	Potential average damage
1	2	34.4%	27
2	3	59%	57
3	4	79.5%	90
4	5	92.3%	135
5	6	98.1%	189
6	7	99.8%	252
7	8	100%	324
8	9	100%	405
9	10	100%	495

At level 1, a bounce isn’t hugely likely, happening only about a third of the time. However, the probabilities rapidly increase as you go up in levels. By level 4, you can expect a bounce to succeed on about 9/10 attempts.

The problem here though, is there is another factor affecting whether a bounce causes damage. You still have to roll to hit. And you’ll need to do this for each hit.

Unfortunately, calculating this with any kind of accuracy is problematic as it entirely depends on the AC of the creatures you’re fighting and your own spellcasting ability.

Generally, a rough 65% chance of hitting is accepted as average for any given level. This means you can expect to hit on 2/3 bounces. Not great odds when trying to land so many hits and those hits being reliant on the next one having a chance. What this means is if we want chromatic orb to be the devastating spell we hope it to be, we need to raise those odds.

How to increase the odds of hitting with chromatic orb

There are a bunch of ways this can be done:

• Increase spellcasting ability score – The most obvious way is to ensure your spellcasting ability is increased as much as possible as this will affect the bonus to hit on your attack roll.
• Increase your proficiency bonus – Along a similar vein, the higher your proficiency bonus, the more likely your spell attacks are to hit. Of course, the only way to do this is by increasing your level.
• Gain advantage – When you have advantage on a spell attack, you can roll the d20 twice and choose the highest roll. This gives you an 88% chance of hitting (when assuming a base probability of 65%). There are several ways to achieve this, some of which are class specific. For example, sorcerers can use innate sorcery to gain advantage on spell attacks for a whole minute. Arcane tricksters can hide as a bonus action to gain the invisible condition which grants advantage on attack rolls (but only for the first attack roll). An arcane trickster might also be able to use the vex weapon mastery property or steady aim to gain advantage on the initial attack roll while the greater invisibility spell could be used for more persistent advantage. You can also grab the lucky feat too.
• Use spells to enhance your spell attacks – There are some spells and similar features that can grant bonuses to your attack rolls. Bless is one of these. Paladins and clerics can cast this as standard or you can grab it through the magic initiate origin feat. It’ll grant an extra 1d4 to attack rolls and saving throws for the next minute allowing all of your chromatic orb attack rolls to get a small, but significant boost for the combat. Bardic inspiration can do a similar thing but for a single attack roll that has missed. Bardic inspiration dice range from d6 to d12 so there’s potential for a significant boost if one of your orbs happens to miss. Handily, bardic inspiration and bless can be combined.
• Use magic items to enhance your spell attacks – Some magic items will confer a bonus to your spell attack rolls when wielded. These include things like; robe of the archmagi, staff of power, staff of the magi, staff of the woodlands, talisman of pure good, talisman of ultimate evil and wand of the war mage.
• Gain reroll attempts – Heroic inspiration lets you reroll any die, including an attack roll. Because this is a reroll, it can be used alongside advantage, potentially giving you 3 d20 rolls to land a hit if needed. A Halfling’s luck will let you reroll 1s on a d20 test increasing your odds a little too.

Is chromatic orb better than other spells?

To understand this, I’m going to take some multi-target damage spells and apply some average damage scores to them to give a bit more context to how well chromatic orb performs. I’ll compare chromatic orb upcast to the appropriate level for a fair comparison too.

Spell (level)	Average damage	Chromatic orb average damage
Magic missile (1st)	10.5	27
Scorching ray (2nd)	21	57
Chain lightning (6th)	180	252

As can be seen, chromatic orb has much greater damage potential than these other spells. And this increases exponentially as spells are upcast.

However, there is a major flaw in the table above. It ignores the chances of hitting and just assumes that every blast hits. In reality, all of the above spells are more reliable at dealing damage than chromatic orb. Magic missile always hits, chain lightning deals half damage on a passed saving throw and all 3 of them have multiple shots that aren’t reliant on the previous shot hitting.

Because of this, chromatic orb has some of the highest damage potential of any spell in the game at every spell level, but in practice, that chain can easily break down leaving you with a more modest or even low damage spell.

But, as shown above, you can build around this making the odds of successive hits quite high. If you and your party are prepared to do this, then chromatic orb can be absolutely devastating to groups of enemies.

Building a character for chromatic orb

Technically, any character can cast chromatic orb with the right options chosen. Your character will need to take one of the following options to be able to cast it:

• Be a sorcerer, wizard, eldritch knight or arcane trickster. All these classes/subclasses have chromatic orb on their spell list as standard.
• Play a bard. With magical secrets, you can take chromatic orb at level 10 (or level 6 if you’re playing a college of lore bard).
• Take the magic initiate origin feat and choose from the wizard’s spell list.

The best build for a more reliable chromatic orb is probably a Halfling clockwork sorcery sorcerer. Between innate sorcery providing constant advantage and Halfling luck for any 1s, you should have a very reliable source of advantage. On top of this, at level 14, you’ll gain a clockwork sorcery features called trance of order. This will ensure all your d20 tests (including spell attack rolls) roll at least a 10, making your attacks almost guaranteed to hit. Especially when combined with other features.

You can also grab magic initiate cleric to grab the bless spell (or have a friendly cleric or paladin cast it on you) and you can even work with a friendly bard for bardic inspiration. The lucky origin feat is also great for when you’ve run out of innate sorcery uses.

As an alternative, you could play a Human clockwork sorcerer for the extra origin feat (allowing you to take lucky and magic initiate) and for a steady supply of heroic inspiration.

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So is chromatic orb a hugely powerful spell? The answer really is, it can be. If you’re able to build around it, you can make it fairly reliable to hit multiple targets. Otherwise, the chances of landing subsequent bounces against enemies are a little too prone to missing and it’s unlikely you’ll hit enough to land the massive damage you might be hoping to cause.

If you’re up for an unreliable, but potentially devastating spell, then this could be the spell for you.

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