Okay, there was a bit of a discussion a while ago about whether it made sense that good deities restrict the use of negative energy, and that evil deities restrict positive energy usage.

...what made the discussion most credible, is when considering the good undead and other negative energy affinity creatures (Despite me only knowing of two.)

Considering I've made my own decision on whether it makes sense or not; I now want to ask the next few questions...

Would removing those alignment restrictions be a bad house rule?
Would it unbalance the game?
Would negative energy paladins of good be too far fetched or out of place?

Or would it do the exact opposite?

Basically, I want to know how stupid or smart such a house rule would be.

Especially in the presence of overly common good undead.

I did that in my campaign, and nobody misses the restrictions.

The Oracle's choice of whether to automatically know all Cure spells or all Inflict spells is made independently of alignment, and an Evil Life Oracle can channel positive energy like a Good Cleric.

You should be able to remove the alignment restrictions safely.

It depends entirely on the rest of your campaign. It's certainly possible to make it work.

For a while I was considering an alignment system which measured both grim vs noble (means) and heroism vs villainy (ends) instead of plain old good vs evil. In that system, negative energy and all spells with the evil descriptor were considered grim, rather than villainous, so a hero could easily use them if he was willing to get his hands dirty.

That kind of grey morality wouldn't fit every campaign, even if it's probably more realistic.

Is it overpowered? Heck no. It gets a little weird with the cosmology sometimes, but if your universe allows good people to channel harmful energy, go ahead and let fly.

That's the nature of house rules. If the rule is acceptable to your house, than it's an acceptable house rule.

Why not go further.... take the Monte Cook route and ditch alignment altogether? It's a bit of work but worth the trouble.

Would removing those alignment restrictions be a bad house rule?

Would it unbalance the game?
Would negative energy paladins of good be too far fetched or out of place?

Negative energy isn't evil, and positive energy isn't good, so there shouldn't be any thematic problem with it. As for game balance, positive energy channeling is far more useful, so the option to channel negative energy, for a good character, is sub-optimal.

Unlike positive energy channeling, negative energy channeling has a save to halve it's effectiveness. Selective Channeling allows positive energy channeling to be easily used with even a Cha as low as 13, against a single foe (such as the climactic 'Big Bad' fight), and careful positioning near the rear of the action allows someone to heal at least some of their allies, without healing any of their foes, simply by stepping back before channeling. On the other hand, Selective Channeling with negative energy requires your party to be undead, dhampirs, etc. *or* your Charisma score to be equal to the number of party members (at *least* three, so 16+, and that's assuming that nobody has an animal companion, familiar, mount, cohort, eidolon, pet, horse, etc. or that you don't have any NPCs or other allies / civilians around you aren't willing to 'friendly fire' with negative energy bursts). And if the evil cleric is blowing all of his point-buy on a high Charisma, to protect his party members, he's going to have less for Wisdom (and Str, Dex and Con), making him less effective at spellcasting and combat support, and, in all ways, inferior to the positive energy channeling good cleric.

A Paladin blasting evil creatures with negative energy shouldn't be any different than his smiting them. Either way, he's using unaligned channeled power to cause harm to his foes. Negative energy isn't any more evil or good than paladin 'smite power.' So long as those foes are evil, and you are playing in a game setting where negative energy is non-evil (which, canonically, is all of them, ever), a paladin using negative energy to 'smite' evildoers should be a mark in the 'good' column.

The option to channel positive energy would greatly increase the effectiveness of evil clerics, on the other hand, as they would be able to heal their own allies, including planar allies like demons, devils and daemons, as well as cultists of their own faiths, all of whom would have been ravaged if they had started blasting away with negative energy explosions. Be prepared for fights with evil clerics in the background to last a round or two longer, as the evil clerics can use the same tactics as the good guys, and hang back and selectively refresh their evil allies. Note that clever movement by your players can help alleviate some of that difficulty, as the evil cleric would then run the risk of 'friendly fire' healing PCs as well as his own living allies (and, as he will likely *always* be facing a 4+ team of PCs, Selective Channeling is not going to be of much use to him...)

Another handy thing for the evil cleric channeling positive energy is that, since you have to choose whether or not you are harming or healing with each use of channeled energy, channeling positive energy to heal has zero effect on undead allies, so the evil cleric can *still* have a bunch of undead minions or allies as well, and heal his living allies without harming his undead allies (whom he can still heal with Inflict Wounds spells, or Infernal Healing spells, if necessary).

The balance issue would be that adding negative energy channeling options to Team Good basically gives them an inferior option to positive energy channeling, while giving positive energy channeling to Team Evil is a significant upgrade that might affect the length of combats that include 'evil healing clerics.'

As a GM, you can exploit or restrict that potential by choosing the encounter location, and setting it in an area where the evil cleric simply does not have enough room to step back and channel-heal only his own allies (without inadvertantly also healing his PC foes), and the PCs can also attempt to foil that strategy through pushing through the lines of his living allies and forcing him to choose whether or not he is willing to heal them, as well as his own allies.

Evil Healing Clerics aren't any stronger than Evil Healing Oracles, which already exist and can actually use Selective Channeling properly to avoid healing the PC's because they use Cha for casting. And the baddies don't benefit as much as the PC's from being able to prepare different spells each day, so being an Oracle instead of a Cleric isn't much of a drawback.

I don't even make Clerics choose. All Clerics are physically capable of both options-- the only difference is whether or not their deity imposes a Code of Conduct restriction. Almost all deities allow positive channel, some Good deities and most Neutral or Evil deities allow negative channel, and so it goes.

Of course, I also take the alignment restrictions off of Paladins and Antipaladins (Blackguards) so your mileage may vary-- Paladins can only channel positive energy and their smites are limited to Evil creatures, while Blackguards can only channel negative energy but they can smite anything. Like in 4e, Paladins are protective and Blackguards are destructive-- but either may be Good or Evil.