I would say that Produce Flame can have multiple targets (similar to the Blinding Smite advice) so is not a valid spell for duplication. Also, steeds don't have hands...
Armor of Agathys on the other hand never targets other creatures, so that should be fine.
I understand what the sage advice is saying and can accept that produce flame wouldn't work but what about armor of agathys?
sageadvice.eu isn't Sage Advice.
As sageadvice.eu puts on every one of their pages, "This is an unofficial D&D site made by Zoltar to collect game designer tweets and help players of the best game ever created." It's neither an official collection of things nor a collection of official things. Each page links to the relevant tweets so you can vet they are real, but Jeremy Crawford doesn't tweet these things in an official capacity, meaning the tweets constitute insight into how 5E's lead designer thinks things should go, but do not constitute binding rules in any sense. Furthermore, JC has tweeted multiple times about some issues, changing stance each time. The big takeaway here is that his twitter feed more or less conveys potentially stale visions of RAI, but not RAW.
Official Sage Advice formally declares that what I said about JC's twitter is accurate. "Official rulings on how to interpret rules are made here in the Sage Advice Compendium. The public statements of the D&D team, or anyone else at Wizards of the Coast, are not official rulings; they are advice. The tweets of Jeremy Crawford (@JeremyECrawford), the game’s principal rules designer, are sometimes a preview of rulings that will appear here."
Find Steed states "While mounted on your steed, you can make any spell you cast that targets only you also target your steed."
Cone of Coldwill work, just not usefully, because it can be cast in a way that targets only you - cast it without any creatures in the AOE other than yourself. A corner case where this could come up is if you desperately need a way to locate invisible creatures - you could cast Cone of Cold and attempt to use Find Steed to damage the steed despite it not being in the cone. If the steed takes cold damage, there were no invisible creatures in the cone. Likewise, if you desperately needed to deal cold damage to your steed and you knew you could cast it in a space with no creatures in it, this would work.
Thunderwave is exactly like Cone of Cold - an AOE of the form Range Self (AOE).
Armor of Agathys will just work, and is a classic primary use-case for the Find Steed ability. Both you and the Steed will get the THP that deals cold damage.
Produce Flame would just work (provided you cast it to only produce the flame - if you attack with the flame as part of the casting, you're targeting the spell attack target with Produce Flame when you cast it, which violates Find Steed; if you only produce the flame and hold it, you're fine), but the spell mandates that the flame appears in the caster's hand. None of the listed steeds have hands. The "common English" definition of hand includes the paw of any monkey or ape, not just the specific ape known as human - an ape has a hand in the same way a dragonborn has a hand, because it's sufficiently similar. Find Steed says your DM may allow other "animals", which generally means the Beast type, per the Monster Manual's definition of Beast. An ape is the same CR as a warhorse, which is in the explicit Find Steed list, and is large enough to carry a Small rider. If your DM permits you to use Find Steed to summon an ape steed, Produce Flame should produce a second flame in the steed's hand.
If you Polymorph a summoned warhorse into an ape, the Polymorph spell and the Find Steed spell will have a bit of a rules conflict - Polymorph overrides "game statistics", which means whatever your DM decides it means. If your DM rules that the Find Steed block simply now applies to the ape because Polymorph only overrides the steed's statblock, this would similarly allow a second flame in the ape's hand.
The reason Produce Flame works is that the spell only targets self - things you do with the flame
I understand that find steed cannot duplicate spells like cone of cold or even thunderwave but what about produce flame? what about armor of agathys?
relevant sage advice: https://www.sageadvice.eu/blinding-smite-and-find-steed-does-the-spell-qualify-for-find-steeds-spell-effect-duplication/
I understand what the sage advice is saying and can accept that produce flame wouldn't work but what about armor of agathys?
I would say that Produce Flame can have multiple targets (similar to the Blinding Smite advice) so is not a valid spell for duplication. Also, steeds don't have hands...
Armor of Agathys on the other hand never targets other creatures, so that should be fine.
thanks man. appreciate it