Being EA and a time to experiment, I created a party of four clerics (one for each diety). I wanted to see how the various Domains compared to each other. The Domains that I choose were: Sun, Battle, Oblivion and Insight. Here's my impression of the domains and how useful they were. I've included a few suggestions on how to improve the under-performing ones.
Sun (7/10)
The character I created here was a Dwarf, so he was able to wield a Warhammer. The special of enemies having disadvantage on Sacred Flames is huge. The spell is almost useless without this ability. With the disadvantage on enemy saves, it becomes a viable ranged option since it ignores cover and light levels that make crossbow useless in many occasions.
The channel divinity is okay, although I totally forgot to use it most of the time. Spell selection is also okay. Fairly balanced and a decent subclass. Depending on your stats, it can make a decent front-line combatant. (As a dwarf, the character had just as much health as most fighters. The only thing lacking is the ability to wear heavy armor.)
The level 6 abilities sound very useful, alas, I never got the chance to use them.
Battle (8/10)
This domain is pretty much your Swiss Army knife character.
You want offence? How about Martial weapons and Magic Missile at first level. Then you get the very fun Flaming Sphere at 3rd and finally Fireball at 5th.
You want defense? You have healing spells and Shield of Faith. Oh, and you can grant yourself temporary hit points once a day too.
The Decisive Strike channel divinity is the channel that I used the most out of all of the clerics in all of the battles, mainly because you're prompted with a "do you want to use it" every time you hit a foe as long as you haven't used it yet. The extra damage is always welcome and the stun can help if the enemy fails their save. No more powerful than Paladin abilities, so well balanced.
Didn't get to try out the level 6 ability. Could be useful, although if the range is only adjacent tiles, might be of limited usefulness.
This domain can easily replace a Fighter and possibly even a Paladin in your party. Very strong.
Oblivion (10/10)
If you thought the Battle domain was strong, you might want to ditch it for an Oblivion cleric. You get Chill Touch as a bonus cantrip so that you don't have to use the rather pathetic Sacred Flame. (Although, in my case, my Cleric was a high DEX Sylvan Elf so she just used a Longbow and didn't use any cantrips.)
Your channel divinity doesn't do a lot of damage, but it is a Point Blank Area of Effect so you can theoretically hit a ton of monsters at one time and if they fail their save they're all poisoned too. This ability can quickly turn the tide of battle at lower levels with the right positioning. At 6th level you do +d6 Necrotic on your first hit which is almost as good as a second attack. Spell selection is decent, if not quite as good as the Battle domain. Sleep can turn the tide of a low level battle. Bane, followed by Ray of Enfeeblement can take the "ouch" out of a melee boss.
The big plus for Oblivion though, which is possibly over-powered, is the "Peaceful Rest" passive ability. After the very first scripted (so the ability doesn't kick in) night-time attack to introduce the surprise mechanic to players, any time you're attacked at night while travelling it's the bad guys who will be surprised. This is a huge advantage. instead of being helpless pincushions for the first round of battle, you get a free round with Advantage on all attacks. My party usually managed to kill 1 or 2 attackers before they had a chance to react! In one ambush by 3 eagles, I killed them all in the first round. This ability alone makes an Oblivion cleric almost a requirement for a decent party. Who needs the healing of a Life cleric when you can just kill everything before it can even shoot at you???
If you're able to give this cleric the Law Keeper background to pick up Martial weapon proficiency, it can make a viable Fighter replacement. Wade into battle to surround yourself with foes and then pop channel divinity and then slice away with a Greatsword. At level 6, your Greatsword will do 2d6+d6+STR. If you want protection, you can always do Longsword with Shield for +2AC and damage of d8+d6+STR. Or, play a Dwarf or Elf where you get either Warhammer or Longsword proficiency for free. Plus, both races have a subrace with +1 WIS.
Insight (2/10)
I played a Half-Elf for my insight cleric. I gave him the Law Keeper background so that he'd be able to use Martial weapons, which is a good thing because this is one seriously under-powered domain. Sure, the advantage on History, Arcana and Nature sounds nice and it certainly kicked in and helped in the Library, but... I suspect that there wouldn't have been any penalty if I had failed all of those checks, so... useful? Probably not.
Spell selection, compared to any other domain, is basically useless. Sure, I used Identify, but only because I had 4 clerics and no Wizard. In fact, not wanting to have a Wizard in your party and using an Insight cleric as a slightly more robust replacement is really the only time one would want to take this domain. Compared to the others, this is seriously lacking in anything useful.
At the very least, it should get True Strike as a bonus cantrip (in addition to everything it already has). Possibly Guidance for free as well. Both would fit thematically, and since they take Actions to use they're almost detrimental except to buff a Fighter in a boss fight where the boss has a high AC.
The other possibility here (which would make the domain much more appealing) would be to have it grant proficiency with the Manacolon Rosary. Currently, the only way to get this that I'm aware of is to pick the Academic background. If it was part of the Insight domain too, then it would offer players a valid choice and would make this kit much more appealing. Adding both the Manacolon rosary proficiency and True Strike as a bonus cantrip sounds like a lot in addition to what it already has, but really, this domain needs help. Currently it really has nothing to offer that makes any noticeable difference in terms of useful abilities.
The channel divinity to grant enemies disadvantage might be useful, but I never used it. Because the character had martial weapons proficiency, I just gave him a Heavy Crossbow and had him stand in the back while the Sun and Battle clerics played tank.
Life (5/10) - from a different playthrough with a party of Fighter, Ranger (Lowlife, so used in place of Rogue), Cleric (life) and Wizard
The ability to use Heavy Armor is nice, especially if you want to dump DEX. However, if you are playing as a character with a DEX bonus (Elf, Halfling, or even Half-Elf and Human) and get 14 in DEX, Chain mail gets you the same AC as Scale + DEX bonus. So your mileage on this will vary depending on your stats.
Not having Bless and Cure Wounds count against your spell selections is certainly nice because otherwise Cure Wounds (at least) is pretty much mandatory, but the rest of the cleric spells aren't anything so special that it matters. I mean, if you're role is dedicated healer, you're not going to be burning your spells slots on Bane or Detect Magic -- you're going to save them to use with Cure Wounds, right? So... even though it totally fits the domain and I would not change it, I have to rate the spell selection as "lame".
Bonus healing from "Preserve Life" is nice, but with Hit Die usage on a short rest, potions, scrolls and other things like Fighter's Second Wind or Paladin Lay on Hands, it's not really a make-or-break thing. It's also very situational in that the target has to be pretty close to death before it's useful (as it caps the healing at 50% of max health). Similarly, the extra +2 to healing spells is nice, but usually not going to make a huge difference.
This domain is okay if you really want to adhere to the classic Tank/Heal/DPS roles because it just screams "Heal". If you pair it with the Law Keeper background you get martial weapons to go with your heavy armor so until Fighters get extra attack at 5th you're a "Fighter with Benefits". For my taste, a more offence-oriented cleric (Sun or Battle) is better because who needs healing if the enemies are all dead and can't hurt you, right?
Seeing as how this is all straight out of the PHB, I don't see any room to change anything, although compared to some of the other domains, it's a bit lacking.
Interesting concept and well thought out. My main party has 1/2 self paladin oath of the motherlabd. Human battle cleric, elven rogue dark walker, elven mage shock arcanist.
This group has waltzed through the game on the classic setting. The mage and wizard have great dexterity. Once the cleric got spiritual guardians, and the mage got fire ball it was all over for the monsters. The dark castle denizens wanted nothing to do with this party, and I avoided all the boss fights with charisma and diplomacy.
@ chris.clark
Try the fire Cleric. Strongest Cleric in my opinion.
Battle, Oblivion and Elemental Clerics are really powerful, no doubt. Law will also get access to Counterspell at lvl 5, which is really strong if mage enemies become common.
Life and Sun are alright, being neither overly strong nor weak, with some fun elements.
Insight feels like a bit of a meme, but at least it still gets the Cleric base kit, which I would say makes it viable even in the worst case scenario. Loremaster is similar; a meme archetype attached to a class that doesn't need archetypes to be good because of their core spell lists.
Typos happen. More so on the phone.
i would give higher marks for the insight and life clerics.
the insight cleric allows to to skip both a rouge and wizard in a limited capacity and when they hit 6th level they are just as a good as a rouge for finding traps, etc.. give them boots of elven kind and they are all set.
while at the mid levels [5-6] with enough magic items the other clerics can tie the life cleric, i'll assume there will be some +1 or better plate options so the life cleric should have the best AC of the clerics when it really matters [eg at the low [3-4] and high levels [7+]], plus, if you skip the fighter or paladin and use the life cleric as the front tank and just have them stand there dodging then how many or how good your attacks are is a mute point, furthermore, while they are dodging they can still cast healing word. so you can keep all or most of the foes ganging up on something almost impossible to hit while still getting first class healing.
of all the elemental clerics, i think lighting is the best, sure it has the lowest damage channel divinity but it is a guaranteed damage, unlike ice, and it has a very useful side effect that can turn the tide in the battle. if a heavy hitting foe fails that dex save then it is out of the fight for at least 1 round possibly several. also elemental clerics give you the spells you need to access hard to reach loot and tactical maneuvers with misty step, fly, levitate and thunderwave. maybe less spell casting damage than the battle but they can also use that wand of lightning so i would put them on level ground.
i would also demote the Oblivion cleric, unless the random traveling encounters become 10 times harder they are of no big threat to the party even if they are surprised.
yellow flower of courage
Great discussion, I appreciate everyone sharing their experiences. I have been struggling to decide which domain I like best myself. It is good to have so many viable options but it does make it hard to decide.
Here are some things I am currently debating:
1. Str vs Wis - I think STR for weapon damage might be better especially once you start getting magic weapons but I like the idea of WIS offensive spellcaster as well. Domains that add offensive spells are great and Guiding Bolt is nice as well but you only get so many spells per day. Plus Sacred Flame really misses a lot and even when it hits you could roll 1 or 2 damage. On the other hand, you don't get extra attacks like martial classes. if you mostly heal and buff Wis is less important but do you need to max it for offensive spells, like if you go with Battle or Elemental domains? I really can't decide if investing in Str or Wis is better.
2. Heavy Armor from Life domain is really nice. Obviously you will have very good AC but dumping DEX can also allow for 16s in Str, Wis and Con which is really nice too. Without the Heavy Armor, I don't think the rest of life domain is especially great. I wish there was a way to get it with another domain or background but maybe that would make them too powerful.
3. Lawkeeper background seems almost mandatory for clerics (at least for me) and not for the martial proficiency. The real selling point is the proficiency in Perception which is great on a cleric especially if you go Wis focused and the only way you can get it unless you play a Half Elf.
I've played lots of Clerics and the are all serviceable, with a few standouts.
Depending on your play style (my style is the best offense, is the best defense, but also have some defense as a backup plan, in case the offense misses), my thoughts are:
*Make your Cleric a Sylvan Elf and choose a good offensive cantrip (option for Paladins as well) - also solves some weapon issues depending upon domain selection. Note to cantrip lovers, Cantrip Feat is presently broken (as in, it does not work).
*Backgrounds aren't as critical for a Cleric, since you have medium armor and if an elf, decent weapon selections. I tend to use Backgrounds on a Cleric to maximize crafting options or to fill in some role-playing aspect my other characters can'f fulfill since they need access to better weapons or armor.
*Tiers
S (Law, Battle)
A (Oblivion, Life)
B (Elemental, Sun)
C (Insight)
I think Life might become a lot more important with the new difficulty settings cranked up, otherwise, Life would move back to B-tier.
For an average play-through, all of the Cleric classes are perfectly fine, but if pushing the performance/difficulty envelope, I would look at the S/A tier to make your adventure a bit easier (in combat).