Spells like Frostbite, Sword Burst, and Chromatic Orb all have them, and I cannot see a pattern to it for the life of me.

I've admittedly spent way too much time focusing on what this asterisk could mean, and I've come up with nothing. Any ideas?

When you click on the spell, the sidebar will open up. Click on "Customize" for those spells. If there is an asterisk, that should mean you have customized something about that spell.

While that was one of my initial thoughts, and I have customized many save based spells to show as attacks, I can add a spell I have never had on my spell list and never customized and it shows an asterisk as well (i.e. Earth Tremor, Feather Fall).  Apologies for the limit of first level spells and cantrips, I haven't experimented with making my character a higher level to see if there are higher level spells that this applies to as well.

*edit: it does apply to mass polymorph as well, and that is certainly a spell I have never added or customized.

Perhaps post a link to your character here for a mod to take a look. 

I misread the thread. I thought you meant in the spell name. I see the effects asterisks in my own now. Not sure why they show up there, but it is consistent!

Yeah, I don’t exactly see a pattern on anything.  At first I thought it was spells that had secondary effects, like additional damage, then I thought maybe it was something to do with components, I even checked the source material on the spells thinking it was something to do with PHB +1 for AL characters. I’m out of ideas thought lol.

From what I can tell at a glance spells that can do multiple different types of damage have the *. Ice Knife and Chromatic Orb for example both have one but Fire Bolt doesn't.

That would fit, except that mass polymorph and a hand full of other control spells also seem to have it.

I had a deeper look at some more spells and there doesn't seem to be any pattern to it I can see. Weird.
I thought I'd found a link just then when everything without a * seemed to be free content. But then Contact Other Plane broke that idea. It's in the Basic Rules and has a *.

I'm curious about this as well.

https://www.dndbeyond.com/forums/dungeons-dragons-discussion/homebrew-house-rules/28599-how-do-i-get-an-asterisk-next-to-a-spell

I couldn't find a pattern either. This is a puzzle.

Well I'm relieved in a sense I'm not the only one not seeing a pattern or an obvious answer.  I was worried I was overthinking it and it was something simple and obvious.

At first, my thought was it might be spells where the effect changes based on either the level it’s cast at, or your character’s level. But it was also on Light and Mage Armor, so I have broadened that theory to be it’s just DnDB’s way of saying the effect is conditional and you should check stuff before just declaring spell effects. For Light, the condition is if you put it on an enemy, they can extinguish it with a save. For Mage Armor, the condition is the spell ends if the targeted creature puts on or has on other armor.

Quote from kcbcollier >>

At first, my thought was it might be spells where the effect changes based on either the level it’s cast at, or your character’s level. But it was also on Light and Mage Armor, so I have broadened that theory to be it’s just DnDB’s way of saying the effect is conditional and you should check stuff before just declaring spell effects. For Light, the condition is if you put it on an enemy, they can extinguish it with a save. For Mage Armor, the condition is the spell ends if the targeted creature puts on or has on other armor.

That makes sense but then Confusion doesn't have a * and it requires you to roll a D10 and consult a table every turn for them to see what they do.
Locate Creature doesn't have a * either and it's conditional on the creature not being Polymorphed or shape changed and there not being running water between you and it.

Yeah, but confusion always requires the same roll no matter the target or the level cast. Same with Locate Creature. I guess I could clarify that I mean conditional based on the way it’s used, not just the conditions for legal use. If the latter were the case, every spell would need an * because there’s rules about what a legal target is, like range, racial immunities, etc.

I am commenting more so I can see the answer than to add anything. I have spent at least an hour today researching this, and can find nothing. The spells that it shows up for seem so unrelated that it is simply crazy. I created a level 19 spellcaster and just added random spells. I could validate that I saw it on the same spells as others. Also, where it showed up was so unexpected, like Tenser’s Floating Disk. I could find nothing in the spells that seemed to indicate a commonality. I had a few theories, like spells that could not be dispelled (instantaneous casting and the like) but none of the theories would fit all the spells. Maybe a moderator will report why the asterisk is there?

Following to hope I get an answer to this question....I am stymied.

The asterisk refers to having more than one Tag on the spell. The spells layout will only show the first tag, so places the * there to show that there are other tags associated to the spell.

If you click on the spell and open in the side bar at the bottom of the page there is the assicuated tags.

Aha! Mystery solved. Thanks for putting us out of our misery, Sorce!

Indeed. I can sleep now.