Rings

Allfather's Ring
Effect: Gives 2 attunement slots and increases miracle effectivenes (only affects miracles with "numbers", such as Heal or Wrath of the Gods; doesn't effect Miracles such as Force or Seek Guidance)

Location: In the Tomb of Giants you have to drop down multiple times. The item is clearly visible near the ladder down to the bonfire before Nito (you don't need to get on the pillar, just spam Q while falling on it)

Amber Tearstone Ring
Effect: Increases shield stability when health is low. Might increase damage reduction, needs further testing.

Location: Just after the first Capra encounter in a locked room (Burg Latchkey) where Griggs used to be

Ashen Ring
Story related, Dropped by Jareel. Does nothing by itself, but allows you to fight hidden black knights throughout the world of Lordran. When all Black Knights and Gwyn (Lord of Cinder) are slain, it will transform into "Gwynevere's Ring". You don't have to wear the ring, you just need to have it.

Description:

"Haunting ash-covered ring"

Ash-covered ring recovered by Gwyn's nameless firstborn from the site where his father linked the flame and rekindled the Age of Fire.

''The ring is cold and powerless, and heavy with old burdens. Why would anyone want it now?''

Known Hidden Black Knight locations: The Ring isn't carried into future NG Cycles, unlike Gwynevere's Ring. Strangely too, dropping the Ashen Ring on the ground, then killing Gwyn, Lord of Cinder as the Ring is still loaded onto the ground still gives you Gwynevere's Ring, but allows you still to take the Ashen Ring on the ground back. Doesn't do much since the latter cannot be carried after the ending.
 * Upper Undead Asylum (Near where you would find the pyromancer hand)
 * Roof of the front of sen's fortress (Jump down to bottom of the Sen's Fortress, climb up the ladder, hit the wall in front of you and climb up that ladder. The hidden black knight is there.)
 * By the right side along the cliffs from Alvina. Go from the Butterfly direction, reach the cliffs and turn right, do not cross the bridge. (where you would find The Eastern set)
 * Above the Taurus Demon boss fight where the 2 archers usually are in the original version

Bellowing Dragoncrest Ring
Effect: Increases magic potency

Location: In front of the Zombie Dragon on the bridge in Cloister of Exiles

Black Dragon's Ring
Effect: The ring increases your damage by 50% but also sets all defense to 0 besides natural defense (Defense given by levels).

Boosts only physical damage.

Does not affect "Mark of stone" bonus

Location: Defeat Kalameet

Bloodbite Ring
Effect: Increases bleed resist by 50%

Location: In Sen's on a ledge near the first rolling ball track. Drop off to the side near the top of the ball track, where Siegmeier is sitting.

Bond to Beyond
Effect: ????

'''NEEDS MORE TESTING. What we know so far:'''

Certain enemies are known to give soft humanity if enough of them are killed before the area's boss is killed (for more information, look here). NOT among those enemies are the mosquitoes that poison you in the Fetid Slagmire. However, with Quelaag dead, it was indeed possible to obtain soft humanity from killing only these poison mosquitoes.

The rate at which one may obtain soft humanity is not clear. With 3 soft humanity it took over 20 poison mosquitoes before another humanity was gained, but with 4 soft humanity it only took 15 kills to gain another. From this, it seems likely that it's not based off of the normal system, and that each kill has a random chance to provide soft humanity.

'''AGAIN, MORE TESTING IS NEEDED. IF YOU HAVE INFORMATION, PLEASE COMMENT BELOW.'''

Description:

Bonds wearer with eldritch truths

Secret forge-bond crafted by Sen on the eve of her Great Inferno, and shared only with Velka.

Sen cafted eyes to see more worlds than any could fathom, and came to realize that the "gods" lifted up by her belaguered Lord were little more than vermin gnawing at the edges of a cosmic tapestry.

Humanity, whatever it is, offers more insight than heavenly wisdom.

Location: Use the Soul of Manus (Need Pale Eye Orb). Examine the statue in Painted World surrounded by spearmen

Cat Covenant Ring
Effect: Get summoned to invade Darkroot

Location: Join the covenant with Alvina

Chloranthy Ring
Effect: Increases stamina regeneration rate

Location: Royal Woods, same chest containing a blue titanite slab in the original game except this time it's a mimic. Starting from Oolacile Sanctuary, cross the bridge, then head left until you come to a small pool of water with the mimic chest partially hidden by vegetation.

Cold Tearstone Ring
Effect: Increases defense when Health is low.

Location: Drained New Londo behind a pillar near the large mob that spawns exploding skulls. Just as you drop down running towards Four Kings.

Covetous Gold Serpent Ring
Effect: increased item discovery by 100.

Location: Just after Pinwheel on the path back up into Catacomb.

Covetous Silver Serpent Ring
Effect: increase in the number of Souls received by 20%.

Location: In the lava area near Ceaseless Discharge. Easy to see on a ledge as you run down to Demon Ruins. Roll through the lava to the ledge to it's left. Then 30fps jump to the item.

Dreaming Dragoncrest Ring
Effect: Gives 5 attunement slots but decreases weapon damage massively.

Note: Damage is decreased by approximately 75%

Locatin: In front of the Zombie Dragon in Dragon's Ravine

Darkmoon Seance Ring
Effect: Open the path to Gwyndolin near Gwyn's Altar bonfire, gives about %10 damage increase to sorceries and pyromancies

Location: Drained New Londo, on the edge of a well, next to an illusory wall. The wall is outside between the two large cathedral buildings on the way to Four Kings. Where a titanite chunk was previously. Video: https://youtu.be/QwpheIdQuqY?t=1571

Darkwood Grain Ring
Effect: Flippin out like ninjas! Performs special roll (slightly faster and with more invinciblity frames) if below 25% equip load

Location: Can be bought from Shiva after joining the forest covenant. Shiva is found in his usual place either in blighttown or the forest.

Dusk Crown Ring
Effect: Grants extra magic casts. Reduces max HP by ~30%

Location: In Oolacile near Elizabeth back behind some grave stones

Embraced Ring
Effect: Increases maximum health/stamina/equip load but reduces souls gained by 20%, Breaks on removal all the same as its PTDE counterpart.

Location: Kill Lautrec, or complete his invasion with the Black Eye Orb as usual

Empyrean Bond
Effect: Increases equip load a medium amount (more than Embraced Ring, less than Havel's Ring), decreases Lightning resist, and gives the effect of silent footsteps similar to Slumbering Dragoncrest Ring

Location: Kill a butterfly in Crystal Caves (Need Pale Eye Orb). Examine the statue near the Sunlight Alter/Drake bridge

Etched Ring
Starting gift. Gives you an ability to make pacts with the Gods:


 * Kremmel, God of Struggle - found in the starting cell. Increases max stamina by large amount, but makes it regenerate a slower rate as well (not holding block is roughly equivalent to holding block without the pact, and then holding block is about 1/5th that speed), and speeds up durability reduction by 5 times.
 * tested with Braced buckler equipped: recharge rate without pact (157 stamina) and without holding block ~3.2 seconds. without pact (157 stamina) while holding block ~15.26 seconds. with pact (158 stamina) without holding block ~15.4 seconds. with pact (158 stamina) while holding block ~1 minute 20 seconds


 * Caitha, Goddess of Tears - found in the first cell on the left. Increases toxic and poison resistance by 300 points, and bolsters a considerable increase to stamina regeneration (Amount seems similar to having the Chloranthy Ring equipped). However, the player receives about 2 times more damage. The factor seems to vary from enemy to enemy. (needs confirmation).
 * Zandroe, God of Greed - found in the first cell on the right. Attack power is increased, (either it needs testing or it doesn't work) however, the player gains 5 times less souls from normal enemies. Boss drop smaller amount of souls as well, the factor varies from boss to boss in range from 1 to 10.
 * Nahr Alma, God of Blood - found in the second cell on the left. The player gains health from slain enemies, however it also drains the player's health over time.
 * Quella, God of Dreams - found at the end of the hall, after killing the sitting hollow. Supposedly forces you to never die, if you die you get stuck in Abyss with no way out.

tested Kremmel, God of Struggle pact with Sorcerer class (no other equipment or buff active checked at level up screen)

Effects on Gameplay
Pacts make your play-through harder. with some positive effects that are net negatives by design.

If you make at least one pact and unequip the ring you will be cursed and the pacts will break. If you don't make pacts you can unequip the ring safely.

The ring is destroyed if you climb up the ladder out the starting corridor w/o making pacts, or if you unequip the ring later on and come back to that ladder.

There are no known benefits from playing with Etched Ring and the pacts, nor from finishing the game with it. When you finish the game the Etched Ring will be removed from your inventory.

P.S. Despite looking like Old Witch's Ring, the Etched Ring doesn't give you an ability to understand Quelaag's sister.

Gwynevere's Ring
Effect: Allows you to get help, while fighting "Gwyn, Lord of Sunlight". Slightly boosts most stats and grants almost 5% more souls from kills.

Stats increments are as follows: +69 max hp, +7 max equip oad, +7 max stamina, +5 poison resist, +1 curse resist, +1 bleed resist.

The specific amount of souls granted it 5%(rounded up)-1.

es: mournwing, instead of 40k, will grant 40k + 40k*(5/100)(rounded up) -1 = 41999.

es: Oneshotting the Ents in darkroot garden will give 121 + 121*(5/100)(rounded up) -1 = 127 Souls.

Location: Get the "Ashen Ring" and kill the four hidden Black Knights and Gwyn, Lord of Cinder. Strangely, if you've left the Ashen Ring on the ground and keep it loaded in, then defeat said Gwyn, you still get Gwynevere's Ring, and the Ashen Ring on the ground remains for you to pick it up.

This Ring is carried into future NG Cycles.

Hawk Ring
Effect: Increases the range of bows. Can be used to open the Artorias crest door in Darkroot.

Location: Found by killing the giant on the roof of Sen's Forge

Hornet Ring
Effect: Increases critical damage. Can be used to open the Artorias crest door in Darkroot.

Location: Next to the fake bonfire just after pinwheel inside of a coffin. Very hard to see

Leo Ring
Effect: Increase counter damage. Can be used to open the Artorias crest door in Darkroot.

Location: Defeat Ornstein after Smough

Lingering Dragoncrest Ring
Effect: Increases the duration of Sorceries by 50%

Location: Defeat the Undead Dragon in the old Centipede boss room

Lithic Bond
Effect: 10% increased health, increased both Fire/Lightning resist and gives 25 poise

Description:

Bonds wearer with earth

One of the three great forge-bonds crafted by Sen, which are now presumed lost.

The lithic bond was sparked by a vision of a world of crushing stone and metal, immovable and eternal, and was worn only while the Goddess forged her heaviest weaponry.

Location: Become cursed (Need Pale Eye Orb). Then examine the statue in the Undead Parish where the Firekeeper soul used to be

Mark of Stone
Effect: Gives 70 physical defense while decreasing sgnificantly your lightning defense.

Usually a bad choice even againt enemies with a seconday source of lighting damage (such as Ornstein)

Location: Given by an ancient dragon when you give it the doll in a dream. You can get there by using the soul of the "Bane of Lordran".

Orange Charred Ring
Effect: Take very little damage from lava. Gives you the ability to understand Quelaag's sister.

It's worth noting that, unlike the vanilla game, you don't lose the ring when going in NG+.

Location: Defeat the Centipede Demon who is now just outside of the lava entrance to Izalith

Poisonbite Ring
Effect: Increases poison resist by 50%

Location: In the Sluiceworks next to the bonfire, behind some breakable crates

Rendal's Ring
Effect: Increases physical defense and lightning resist by 50. Is removed from the inventory when you go to the next NG+ cycle.

Location: At the top of Sen's drop down to the wooden grating from the catwalk with the Balder Knight, then drop below to a metal beam. The corpse isn't visible from the grating you first land on, only when standing on that beam.

Ring of Ephemera
Effect: Increases action speed by 10-20%, reduces max HP by ~50%.

Location: Dropped by Ornstein, Scion of Naught. (kill red phantom Smough first)

Description:

''Fickle ring sometimes found in the wake of ensouled illusions. Frees its wearer of earthly substance and grants unnatural speed. ''

''The phantoms of phantoms have no place in this world, and are condemned to undulate through time for all eternity. What monster would knowingly create such a being?''

Ring of Sacrifice
Effect: Prevents losing souls on death

Location: Behind the Sluiceworks bonfire on the opposite side of the round chasm. Trade Snuggly an Egg Vermifuge

You can get an exchange for Cracked Red Eye Orb from Snuggly the Crow

Ring of the Rock
Effect: Increases equip load by 40% (10% less than the vanilla counterpart). This is a rename of Havel's Ring

Location: Complete Havel's questline where he kills Seath, then he will drop this ring in Ash Lake near the Everlasting Dragon.

You can also kill Havel either in Duke's Archives or where the Eternal dragon used to be (he will not drop his set, only the ring). If doing Velka's path, this should only be done if Seath hasn't escaped the Archives.

A very good strategy is to not open the door that leads outside the prison in the Archives an drelease Havel while the Capricious Fiend is nearby. The Boss will attack Havel too, so you can just watch them fight and take down the low-health "winner". You might lose the ring if the Fiend kills you after Havel is dead though.

Ring of the Sun Princess
Effect: Boosts Miracle synergy

Location: Join the covenant with Gwynevere

Ring of the Sun's Firstborn
Effect: Boosts Miracles power by 50% (does not affect miracles without "numbers", such as Seek Guidance of Force)

Location: After you come back to the Undead Asylum, drop down to the right of the stairs in front of the room where Oscar was

Ring of Temptation
Effect: Boosts souls received from fallen enemies by 50% but when you die, you lose all your souls and soft humanity (the number in the top left by your HP and stamina bars). Your green death marker still is placed, but will always have 0 souls and 0 humanity. (Ring of Sacrifice does not save the souls, but save humanity).

This ring does not break on death and can be safely unequipped and reequipped. Seems to have a cooldown when equipped, will not take effect for several seconds, meaning you cannot hot swap it at the end of a boss fight to gain its benefits before the souls are acquired. Removal of the ring will immediately end its effects, allowing you to spare yourself losing your accumulated souls.

Location: Undead Asylum drop down the Asylum Demon and then climb up the ladder. Trade Snuggly a Sunlight Maggot.

Rusted Iron Ring
Effect: Movement will not be impaired in swamps, water or such.

Location: Behind the second Titanite Demon in the bottom floor of Sen's Forge.

Serous Bond
Effect: Walk freely in water (Rusted Iron Ring) and increases Fire resist a lot (ideal for lava running)

Location: Walk through Ash Lake and wait until the Hydra finishes it's jump across the sandbar (Need Pale Eye Orb). Examine the statue behind Frampt in Firelink

Tiny Being's Ring
Effect: Increases healing received by ~15%. Also Increases item discovery by 100, similar to gold serpent.

Location: Oolacile Township by Gough on the other side of the stairs up to him

Twilight Ring
Effect: Turns you invisible (Ring of Fog)

Location: Defeat the Twilight Vagrant in the pre-lordvessel DLC

Wolf ring
Effect: Provides 40 points of poise, same as PDTE counterpart. Can be used to open the Artorias crest door in Darkroot.

Location: In the abyss area in Oolacile behind the hidden wall near the last shortcut elevator. Where sif used to be.