This is my idea for epic level rules after hearing some of the complaints.
The big problem i've heard about epic is the system starts to fall apart i think the problem is when characters start getting +20 to rolls the d20 roll itself matters less.
so my idea is at mythic level (21-30) instead of a d20 you start using a d30
mythic monsters would use d30's as would mythic characters they would threaten crit on 30 instead of 20 19-20 would become 29-30 etc. now generally the downside here would be criting far less and failing far less (the failing far less often is a good thing for mythic) however with feats like improved crit and maybe a mythic improved crit they would still work them self back out say a bow would be 30 then impr 29-30 them mythic 27-30.
skill check would remain the same difficulty and higher ones could be imagined.
it may not be necesary but certain saves ac etc could have the fomula bumped up from 10 to 15
and for level above 30 so 31+ you would use a d40 and bump up the numbers agian.
to deal with spell casters one idea ive posted before was having every 2 caster levels increase the save for their spells by 1 i wouldn't make higher spell slots past 10 i would just allow meta-magiced up spell slots.
The advantage would be that now mythic characters chances of failing on menial tasks has gone down. there is now a greater variance on rolls so you can still keep that sweet spot feeling of hitting missing on the middle.
I would like feed back on this idea so please post away ill post some more ideas how to round out this method later