Spells like Conjure Animals and Web can conjure creatures (a wolf) or objects (a sticky web). While the conjuration itself is magical (it was created by a spell), the effects of a conjuration are not necessarily magical. For example, this answer to “Do attacks from Conjure Animals creatures count as magical?” explains why an attack from a conjured owl is nonmagical.
According to the standard criteria, It seems like most effects caused by conjurations are nonmagical. For example, slipping on a pool of grease created by the Grease spell seems nonmagical:
- Is it a magic item? No, it’s a pool of grease
- Is it a spell? Or does it let you create the effects of a spell that’s mentioned in its description? No, it’s a pool of grease
- Is it a spell attack? No, it’s a pool of grease
- Is it fueled by the use of spell slots? No, it’s a pool of grease
- Does its description say it’s magical? No, it’s a pool of grease
However, a similar argument could be applied to evocation spells, like Spirit Guardians and Wall of Fire. But intuitively, the effects a wall of fire (and most evocations spells) should be magical.
Are the effects of a creature or object created by conjuration magic always nonmagical? For example, does a creature with magic resistance get advantage on save against falling grease?
- If so, does a similar argument apply to evocation spells?
- If not, how do we determine which conjurations can have nonmagical effects?