A result of 75 or 76 on the Wild Magic Surge table triggers this effect:
You glow with bright light in a 30-foot radius for the next minute. Any creature that ends its turn within 5 feet of you is blinded until the end of its next turn.
Does this blindness affect the sorcerer who triggered the surge (since she will always be within 5' of herself?
Or are only other creatures affected by it?
This is similar to Aura effects in that:
You glow with bright light in a 30-foot radius for the next minute
While this doesn't use the word 'aura', the mechanical effect is similar in that you are the effect emanates from you in a specific radius. If we utilize this mechanical similarity, we can look at other Aura effects or spell effects with similar mechanics.
These all have different language in how the aura works that state (pulling from Paladin's Aura of Protection):
whenever you or a friendly creature within 10 feet of you...
Aura of Life also has differing language that states:
Each nonhostile creature in the aura (including you)
Every mechanic that involves something emanating from yourself includes langauge like the above. I have yet to find any mechanic that shows otherwise.
Reading it as-is does seem like you count. The only reasoning I've got otherwise I have above, but in a vacuum the blindness would extend to you. However, the support I've given above does strongly suggest that you aren't included by the absence of language that includes yourself.
Only other creatures are affected by this, because the rule does not state that you are affected; only other creatures within 5 feet of you.
You glow with bright light in a 30-foot radius for the next minute. Any creature that ends its turn within 5 feet of you is blinded until the end of its next turn.
Unlike the result of 95-96, it explicitly states that you are affected (emphasis mine):
95-96. You and all creatures within 30 feet of you gain vulnerability to piercing damage for the next minute.
The general rule of thumb is that if a rule does not state something, than it does not include that thing. In this case, it would state that you are also blinded. Since the rule does not state this, you are unaffected.
75-76 You glow with bright light in a 30-foot radius for the next minute. Any creature that ends its turn within 5 feet of you is blinded until the end of its next turn.
She is a creature within a radius of 5 feet (0 even, she is the point of origin) and she will be blinded. She isn't exempt from effects unless the description states otherwise. If someone casts fireball on themselves, they will be affected. A radius effect always includes the point of origin, unless it is explicitly stated otherwise. The effect would have to establish that you are exempt from the radius of creatures that forms an n-sphere on which you are the point of origin of the diameter.
A radius is a well-established term, and it includes the point of origin and the diameter of the shape. Further, it is well-defined what in that radius is affected: all creatures are affected. You are a creature, and no further text is required that specifies this.
For all purposes, it is phrased like a Sphere (PHB 204):
You select a sphere’s point of origin, and the sphere extends outward from that point. The sphere’s size is expressed as a radius in feet that extends from the point. A sphere’s point of origin is included in the sphere’s area of effect.
A sphere’s point of origin is included in the sphere’s area of effect. This is also true for aura type of effects which have the person as the point of origin, and when you compare it to other rolls on the Wild Magic Surge table (PHB 104):
95-96. You and all creatures within 30 feet of you gain vulnerability to piercing damage for the next minute.
You will notice that the wording is distinct. It makes this explicit that the 95-96 roll doesn't use a radius and indeed would have to establish that you are included in that effect, and it does exactly that.
The 69-70 roll would not affect her because it doesn't establish that it uses a radius or that you are affected.
69-70 Each creature within 30 feet of you becomes invisible for the next minute. The invisibility ends on a creature when it attacks or casts a spell.
Compare moreover how the 89-80 invisibility effect is also distinctively worded that you are affected, not creatures within a radius or creatures within x feet of you:
89-90 You become invisible for the next minute. During that time, other creatures can’t hear you. The invisibility ends if you attack or cast a spell.
The wild magic result in question says:
75-76 You glow with bright light in a 30-foot radius for the next minute. Any creature that ends its turn within 5 feet of you is blinded until the end of its next turn.
There are 2 effects being mentioned in this result:
Sentence 1 states a bright light is created. That has a stated radius effect centered on the caster.
Sentence 2 states that any creature within 5 feet of you is blinded. It does not state that the caster is affected by this blinding effect. Using other entries from this table as a comparison:
Affected:
89-90 You become invisible for the next minute. During that time, other creatures can’t hear you. The invisibility ends if you attack or cast a spell.
and
95-96. You and all creatures within 30 feet of you gain vulnerability to piercing damage for the next minute.
Not affected:
69-70 Each creature within 30 feet of you becomes invisible for the next minute. The invisibility ends on a creature when it attacks or casts a spell.
I fully grant that this last one is an odd effect, but if you're expecting sense from a wild mage you're more likely to get potato soup.
