RAI Thought Experiment/Discussion: invisibility via Disguise Self

[MaxWilson]

Inspired by a different thread, and a party full of goblins and halflings:

Disguise Self and Seeming allow you to make a creature look "seem 1 foot shorter or taller." What happens when a creature is already less than 1' tall before casting the spell? Can they become invisible and/or gain the benefits of Greater Invisibility? By RAW they cannot, I know, but I'm asking how you'd actually rule as a DM--what would actually happen at your table if:

(1) A 2'9" halfling wild sorcerer shrinks to 12 inches via repeated wild surges and then casts Disguise Self to appear one foot shorter?

(2) A druid wildshapes into a spider and then someone casts Seeming on them to make them look 1' shorter?

(3) A goblin mage has someone cast Reduce on them to shrink to 1'10", casts Alter Self to alter their height to 10" tall and then casts Disguise Self to appear 1' shorter on top of that?

Can other people visually detect these mages? Do they get advantage on their attack rolls? Do attackers have disadvantage to hit them? Can you cast spells that require sight, like Feeblemind, on them? Does anything change visually if they put on a Ring of Invisibility?

How would you rule, besides throwing a book at the player who did this? What happens in your gameworld in these situations?

-Max

[Unoriginal]

Inspired by a different thread, and a party full of goblins and halflings:

Disguise Self and Seeming allow you to make a creature look "seem 1 foot shorter or taller." What happens when a creature is already less than 1' tall before casting the spell? Can they become invisible and/or gain the benefits of Greater Invisibility? By RAW they cannot, I know, but I'm asking how you'd actually rule as a DM--what would actually happen at your table if:

(1) A 2'9" halfling wild sorcerer shrinks to 12 inches via repeated wild surges and then casts Disguise Self to appear one foot shorter?

(2) A druid wildshapes into a spider and then someone casts Seeming on them to make them look 1' shorter?

(3) A goblin mage has someone cast Reduce on them to shrink to 1'10", casts Alter Self to alter their height to 10" tall and then casts Disguise Self to appear 1' shorter on top of that?

Can other people visually detect these mages? Do they get advantage on their attack rolls? Do attackers have disadvantage to hit them? Can you cast spells that require sight, like Feeblemind, on them? Does anything change visually if they put on a Ring of Invisibility?

How would you rule, besides throwing a book at the player who did this? What happens in your gameworld in these situations?

-Max

Well, Disguise/Seeming make you look a foot shorter in those cases.... which means that you now appears as a visible 2d spot on the ground.

I would certainly give someone attempting that advantage on DEX (Stealth) checks, but not the "can always try to hide" part of invisibility.

I would also give them advantage on attacks (because it'd be hard/confusing for opponents falling for the illusion to see where the attack aims) but no disadvantage to the opponents targeting them, aside from the usual benefits of being Tiny (they can see in which spot you are, or rather which spot you are).

[king_steve]

My interpretation is that you appear proportionally shorter, e.g. if I am medium sized creature that is 5' 6" and I appear 12" shorter then I would expect to look like a similarly proportional 4'6" creature.

In the situation your not a medium creature, I'd probably adjust the size based off the starting size class, for example the 2'9" halfling might be 6" tall and I'd probably say they'd appear to be a tiny creature.

An off the cuff change might be to adjust the size so if you start at medium you appear 12" taller/shorter, small you appear 6" taller/shorter and tiny you appear 3" taller/shorter? That feels okay off the cuff, but I'm not 100% sure that would apply to all creatures of a given size category.

Maybe it should be proportional? You appear up to 25% larger/smaller?