Rule 001: Drowning for Health Purposes.
While strict RAW indicates that you can raise someone from negative hit points to 0 hps in the first round of that individual having failed to hold their breath underwater, this ruling clearly makes no sense. The intent (a DROP to 0 hps) would seem to be clear and much more logical. As such, the following rule is now in effect:
Replaces DMG p304, second paragraph of Drowning: "When the character finally fails her Constitution check, she begins to drown. In the first round, she falls unconscious; and is reduced to 0 hp (unless already below that point). In the following round, she drops to -1 hit points (unless already below that point) and is dying. In the third round, she drowns (and is dead)."
Rule 002: My Thesis: More Complex Is Easier.
As has frequently been pointed out in a number of builds, Arcane Thesis is a cornerstone of metamagic-reducing builds. By applying metamagic to a spell, you can get the enhanced, modified spell to use up a spell slot one level lower than normal. The text of this feat, however, seems to ignore that there are a selection of feats (yes, even ones published earlier than the PHBII) that already add 0 levels to the slot. Thus, by applying a 0-level metamagic, you can actually DECREASE the level of the spell.
Another common cornerstone for reducing the cost of Metamagic is the Incantatrix prestige class from the 3.5 Player's Guide to Faerun. At 10th level, the incantatrix gains a similar ability that reduces the required increase in spell level, though with a minimum of +1 spell level. This, to my mind, sets something of a precident. Combined with the idea that it shouldn't be EASIER to cast a spell just by adding metamagic components to it, regardless of the number and manner of reducing abilities you utilize (there are others...thus, the rule will be a blanket one), I would propose:
Override for all forms of Metamagic cost reduction: "The application of any individual metamagic feat cannot reduce the spell level of the overall spell. The minimum reduction applied by each individual metamagic feat is +0, regardless of the method utilized to achieve said reduction."
Rule 003: Bonus Legacy Class Levels.
The Legacy Champion (Weapons of Legend) is a very unique prestige class, in that it tries to cover every possible contingency of "more of what you would get if you were still in your regular class" while giving its legacy-related benefits. The intention here seems plain...if you're a Barbarian 10/Legacy Champion 10, you 'count' as being a Barbarian 18 in nearly all respects. If you're a Rogue 10/LC 10, you're basically a Rogue 18, and so forth. This seemed to be a much more efficient approach than to try and create a dozen different Legacy Champion classes...the Legacy Champion Warior, the Legacy Champion Wizard, etc.
Once again, however, some creative individuals have been able to utilize this in a manner that, as far as I can tell, goes well beyond the intent of the class...the ability to continue getting levels in a class, typically a prestige class...that otherwise wouldn't HAVE any more such levels.
The most popular use I've seen for this particular bit of slight of hand is the Hellfire Warlock (Fiendish Codex II, p. 89+). It's an unusual class, in that it only has 3 levels to it...and unlike the regular Warlock (who's eldrich blast only improves by +1d6 per two levels), the Hellfire Warlock improves at the rate of +2d6 EACH LEVEL. I, personally, am assuming that this advanced rate of progression is mitigated by the fact that there are only 3 levels to the class.
Others would disagree, and by combining the Hellfire Warlock with the Legacy Champion, manage to get 11 levels' worth of +2d6s to the Eldrich Blast ability. Whether or not this is reasonable, necessary to 'fix' the Warlock, and so forth is entirely irrelevant as far as I'm concerned...my issue with it is that the Legacy Champion would appear to be intended to keep your regular progresison going, not to stretch a class beyond its limits.
Since I am not sure if there are other sources besides the Legacy Champion that introduce similar "+1 level of your class features", I therefore propose:
Limit to Class Features: "No class (base or prestige) can have its class features progressed beyond the maximum printed level of the class itself, save for the specific exceptions spelled out in the rules for epic progression."