Can an Illusion of Cats Damage a Rat Swarm?

[Mistwell]

I just don't understand all this "they lack smell therefore it won't work" claims. If you think the rats are interacting with the illusion to attempt to detect a scent, then they get a saving throw. That is how illusions work - you interact, and you get a save to detect that it is an illusion. It's not automatic.

I mean - the scentbane spell, and similar spells, are low level spells. You are essentially saying that any spell, or magic item, that makes you scentless will make you essentially invisible to any animal that uses smell as a primary sense - because they will automatically assume you are an illusion if they cannot smell you. Great! So you might be nerfing some illusion spells, but you are WAY powering up the scentbane type spells and items.

That is, unless you would assume an animal with a good nose would ALSO perhaps rely on it's eyes. In which case we are back to it being an effective tactic to use an illusion spell as proposed in this thread.

Pick a position - scentbane is powered up, or illusion spells can trick animals with good noses if they fail their saves.

 

[Diirk]

In the D&D world rat swarms are immune to damage from cats anyway; eventually they'd pick up on this and lose all fear of cats imo.

 

[KarinsDad]

In the D&D world rat swarms are immune to damage from cats anyway; eventually they'd pick up on this and lose all fear of cats imo.

Except that we were discussing a Cat Swarm, not a Cat.

Rat Swarms take half damage from piercing and slashing.

A Cat Swarm in DND would do approximately the same 1D6 damage per round that a Rat Swarm does. So a Rat Swarm would not be immune to the damage from a Cat Swarm, just like a Rat would not be immune to the damage from a Cat.