15 Jul Disguise Self 5e D&D Guide 
The option to change their appearance completely can be critically important for some characters. Disguise Self does just that. Limited to only changing appearance, though, it can have limited impact and will often falter under intense scrutiny.
The rules for Disguise Self can be found in the Players Handbook on page 233.
Disguise Self 5e
Illusion 1st Level
Casting Time: 1 Action
Components: V, S
Duration: 1 Hour
You make yourself–including your clothing, armor, weapons, and other belongings on your person–look different until the spell ends or until you use your action to dismiss it. You can seem 1 foot shorter or taller and can appear thin, fat, or in between. You can’t change your body type, so you must adopt a form that has the same basic arrangement of limbs. Otherwise, the extent of the illusion is up to you.
The changes wrought by this spell fail to hold up to physical inspection. For example, if you use this spell to add a hat to your outfit, objects pass through the hat, and anyone who touches it would feel nothing or would feel your head and hair. If you use this spell to appear thinner than you are, the hand of someone who reaches out to touch you would bump into you while it was seemingly still in midair.
To discern that you are disguised, a creature can use its action to inspect your appearance and must succeed on an Intelligence (Investigation) check against your spell save DC.
The rules for Disguise Self explain how the transformation takes place and what is changed. They present the limitations of how much the physical appearance can be altered. Also described is the possibility of someone seeing through the disguise and how that can happen.
How does Disguise Self Work?
Casting Disguise Self changes the physical appearance of the caster. The description clearly outlines the possible alterations that affect the physical proportions, armor, weapons, and items of the caster. A difficulty check of intelligence versus spell save could reveal the illusion. There are some interesting challenges that could be made to the rules based on exact wording and practicality.
The spell allows for manipulation of physical dimensions of 1 foot taller or shorter and wider or thinner. There is not any clarification on what happens if changes take place outside of those boundaries.
For example, there is no clear rule provided for the interaction of Disguise Self and Enlarge/Reduce. This would cause the disguised creature to grow proportionally outside of the 1-foot restraints. This is a DM interpretation of exactly how the spells function together.
The rules also do not elaborate on the actual effects that can be used on the weapons, armor, and items. It would technically be possible for the items appearance to change completely, forcing a DM ruling. For example, a shortsword made to look like a dagger could catch someone by surprise if they could only see the length of the dagger.
Does Disguise Self Alter Voice?
The spell does not alter voice in any way. It would be stated in the rules if that was part of the spell function. The spell Alter Self does allow for complete mimicry of the disguise taken. Disguise Self only alters the physical appearance of the caster and their possessions.
Can you Cast Disguise Self on Others?
The spell has a range of self, making it affect the caster only. There are other spells that allow the caster to change the appearance of others, though. Seeming is one option, although it is a 5th level spell. Polymorph would also provide the ability to change the appearance of another individual, but the target takes on the traits of the creature.
Is Disguise Self Concentration?
Disguise Self has a duration of 1 hour with no concentration required. This leaves the caster free to perform other activities that require concentration while disguised. It also means that while combat may reveal the illusion is present, it cannot be lost due to damage.
The lack of a concentration requirement means that Disguise Self will last even if the caster is incapacitated. The spell will run the length of the duration unless voluntarily removed by the caster. Obviously, interaction with the body will reveal the presence of the illusion. This should add difficulty to a medicine check made on the caster.
What are Creative uses for Disguise Self?
- The caster can use disguise self to change their appearance to match the surroundings like camouflage.
- The caster could give themselves a blurry appearance to simulate the Blur spell.
- The caster could change their appearance to show as an elemental type being, fire or ice skin, for example.
- The caster could change their appearance to 1-foot shorter and peer over walls undetected.
- The caster could change their appearance to match a bipedal enemy causing confusion among the ranks.
Illusion spells seem to be some of the most difficult spells to nail down. They are often presented with enough rules to make them functional but also vague enough to potentially cause issue or confusion.
This is no different with Disguise Self, the majority of the effect comes down to DM interpretation of how the spell works in the world. As always, its best to discuss potential uses for the spell with the DM before committing to avoid disputes mid-session.