Monsters that come with combat buffs

[shadow_archmagi]

Spellcasting monsters and NPCs often come with a note on their spells that says "It casts these spells on itself before combat." I've always interpreted this as a statement about the monster's preferences, mentally editing it to "If forewarned, it attempts to cast these spells before combat." A fellow DM interpreted the line not as a suggestion, but as crunch. "Did a combat start? Then those spells were cast." I'm curious as to the opinions of others.

[nickl_2000]

I guess it depends on the spell to me. If it's a spell like Mage Armor that lasts 8 hours, I would probably consider it as something that the monster casts on itself all the time. If it's something that last less than an hour, I would go with forewarned.

On the other hand, if the DM needs that monster to have that in there to make the encounter the correct challenge rating, then the DM can do whatever they like.

[Unoriginal]

Spellcasting monsters and NPCs often come with a note on their spells that says "It casts these spells on itself before combat." I've always interpreted this as a statement about the monster's preferences, mentally editing it to "If forewarned, it attempts to cast these spells before combat." A fellow DM interpreted the line not as a suggestion, but as crunch. "Did a combat start? Then those spells were cast." I'm curious as to the opinions of others.

The first interpretation in the correct one. It's "before engaging combat, they will cast those spells if able" not "they can retro-actively have casted those spells in advance whenever a combat start".

If they want to cast them on the first few rounds of combats, it'd take them actions like for everyone else.

Though as mentioned before some buffs can just be on constantly if they can afford it.