I agree.... and disagree.... (how is that for fence sitting
)
In general, throwing 400 kobolds against a 13th lvl party is pretty silly, and not much of a challenge. As stated, once you start adding a lot of low CR, it just doesn't add right. (I get suspicious at/around 8 creatures)
OTOH, yeah, people are right. 400 Kobolds *could* be a force to deal with. *IF* there are unusual circumstances that would bolster the EL.
If they had the extra 1000's of gold to be buying tanglefoot bags
If somehow you could get 400 together, with no non-combatants; and they all had a crossbow.
If you were attacking their well prepared lair.
If they had an 'unusual' leader that could provide better than usual leadership and ideas.
etc.
Believe me, give me 200 kobolds in their lair, with an 'unusual' leader, and that party of 13th level will feel lucky to get out alive
So, by opinion of Does 400 kobolds = EL13?
Could be yes, most likely, no.
.

In general, throwing 400 kobolds against a 13th lvl party is pretty silly, and not much of a challenge. As stated, once you start adding a lot of low CR, it just doesn't add right. (I get suspicious at/around 8 creatures)
OTOH, yeah, people are right. 400 Kobolds *could* be a force to deal with. *IF* there are unusual circumstances that would bolster the EL.
If they had the extra 1000's of gold to be buying tanglefoot bags
If somehow you could get 400 together, with no non-combatants; and they all had a crossbow.
If you were attacking their well prepared lair.
If they had an 'unusual' leader that could provide better than usual leadership and ideas.
etc.
Believe me, give me 200 kobolds in their lair, with an 'unusual' leader, and that party of 13th level will feel lucky to get out alive
So, by opinion of Does 400 kobolds = EL13?
Could be yes, most likely, no.
.