I've been playing for 7 years. I've seen the game going from a single class kind of character game to one where it is possible to multiclass and I prefer the later. There is only one kind of multiclass tho that it isn't possible to do without being too lame: DC casters multiclass. Moreover, being a DC caster maxed in one class is usually not accurate most of the time if you don't have all the past live and gear to do so. In order to change that, I suggest one implementation on the casters skill trees, as a feat or as power on items: the spell save bypass.
On skill trees it could be a tier 4 or 5 skill with 3 levels each costing 2 sp points and reading as such:
tier 1: 10% chance that the the target automatically fails his save against your spell thus allowing effect or dmg fully
tier 2: 20% "
tier 3: 30%
percentile are only a suggestion, but the effect of spell bypass could help multiclass dc a bit and would still need at least 20 sp to get in one tree
A feat could be 25% fixed chance to bypass spell save and be available only with prerequisite in stats or feats
On items it could be a random % and put only on rare items and on augments
I wouldn't suggest to put spell bypass on all three (skills, feat and items) but only on one of them. The suggestion is not to give a chance to casters to become OP again, but to make available more kind of multiclassing and help with overall DC casting...
What do you think about the idea?