Death Knight

Introduced in the Wrath of the Lich King expansion, the Death Knight is World of Warcraft’s first (and currently, only) Hero Class. These shadowy, immortal soldiers are former slaves of the Lich King, and fight with emblazoned Runeblades. They utilize a combination of melee strikes and dark magic to empower their abilities, also holding dominion over various undead creatures to do their bidding. Where most other classes would begin at level 1, a Death Knight begins at level 55 and must complete a unique starting experience that no other class has access to. Beginning at a high level means that in order to unlock a Death Knight, a player must have at least one other level 55 character on the account that they wish to play a Death Knight on. As of the Mists of Pandaria expansion, players are no longer limited to one Death Knight per realm.

Death Knights are melee fighters, capable of utilizing the Frost and Unholy specializations to DPS, and the Blood specialization to tank.

Boosting to 90

One of the perks of being a Death Knight is their ability to emblazon their weapons with powerful Runeforges. Runeforges are unique, and completely replace traditional weapon enchants for Death Knights.

Unlike most classes, Death Knights have trainers in only one location: The Ebon Hold (located in the Eastern Plaguelands). In order to reset specializations and enchant their weapons with Runeforges, Death Knights must visit this citadel. This is made easier by the Death Gate spell, which directly teleports the Death Knight to the Ebon Hold.

With the exception of Pandaren, any member of a race may become a Death Knight. With Warlords of Draenor, the rebalancing of different racial bonuses and updates to various character models leaves the choice of race largely up to the aesthetic or thematic preferences of the player.

Because they already begin at a higher level, playing a Death Knight assumes familiarity with basic mechanics of the game. Before boosting your Death Knight to 90, it is strongly recommended that you familiarize yourself with the fundamentals of their resource system and spec design. Fortunately, the starting experience is an excellent opportunity for this!

The Rune system is a resource structure unique to Death Knights. No other class in the game can be said to have a system that is similar or, arguably, more engaging. Mastery of the Rune system is a core component of learning how to play a Death Knight.

Class Abilities and Resources

Runes

Runes are a resource split into three types: Blood, Frost, and Unholy. A Death Knight’s Rune Bar consists of one pair of each—that is, two Blood, two Frost, and two Unholy Runes.

Different Death Knight abilities cost different types of Runes. Scourge Strike, for example, costs one Unholy Rune. Death Strike costs an Unholy and Frost Rune pair. When an ability that costs Runes is used, those Runes go on cooldown, and cannot be utilized again until they have finished recharging.

Runes of the same type refresh sequentially. This means that if, for example, both Blood Runes are recharging, then the actual recharge period for the second Blood Rune does not begin until the first one has finished recharging.

On the other hand, Runes of different types may refresh concurrently. Thus, if an ability utilizes both a Frost and Unholy Rune, both Runes should begin recharging immediately, assuming the other Rune type in their pair is not currently recharging. The base recharge time for a Rune is 10 seconds, though certain talents and the Haste stat can decrease this time.

Additionally, some abilities and talents in the game can cause Blood/Frost/Unholy Runes to return as Death Runes. Death Runes can take on the functionality of any type of Rune (meaning they can be used in place of any Blood/Frost/Unholy Rune), and thus act as a measure of versatility in otherwise strict situations for abilities with rune costs.

Runic Power

Utilizing Runes generates a secondary resource known as Runic Power. Like Runes, certain abilities can cost Runic Power. This can range from damaging abilities such as Death Coil or Frost Strike, to more situational abilities such as Dark Simulacrum. Several “free” Death Knight abilities can be glyphed to have shorter cooldowns, but with an added Runic Power cost. Runic Power caps at a maximum of 100.

The most important thing to understand about Runic Power is that how it interacts with the level 60 (i.e. Rune Regeneration) talents. Spending Runic Power gives two of these talents (Runic Corruption and Runic Empowerment) a 1.5% chance to proc per point of Runic Power spent, and causes Blood Tap to generate 1 Blood Charge for every 15 Runic Power spent. These talents then go on to further generate Runes themselves.

Put together, Runes and Runic Power create a feedback loop: Spending one will generate the other, and thus a Death Knight will ideally be constantly spending resources without allowing either to cap.

Presences

Similar to the Stance system of the Warrior class, Presences are mutually exclusive auras that the Death Knight is able to shift into. Each Presence corresponds to the name and theme of a Death Knight specialization, though they are all usable by all specializations.

In general though, a Death Knight will want to utilize the presence that corresponds to their specialization. Thus, Frost Death Knights will want to remain in Frost Presence most of the time, while Unholy Death Knights will utilize Unholy Presence. There can be brief situations where a Death Knight may wish to switch presences, but doing so will usually consume all stored Runic Power and provide a much lower performance gain (i.e. less damage for DPS and much less survivability for Tanks) than the intended Presence.

Soul Reaper

Unique for both its effect as well as its iconic nature, Soul Reaper is the Death Knight Execute. While most shared abilities between different Death Knight specializations retain the same cost, Soul Reaper’s cost changes according to the spec that uses it—Blood Rune for Blood Death Knights, Unholy Rune for Unholy Death Knights, and so forth.

Additionally, where most Execute type abilities only become usable when a target is at 20% or lower health, Soul Reaper differs in two aspects:

Its physical “strike” component can be utilized at any health percentage for the target.
Its shadow “detonation” component only occurs when the target that has been afflicted with Soul Reaper is at 35% (45% for Unholy DK) or lower health, 5 seconds after the physical strike.

Because of this, Soul Reaper is not a “fire and forget” type button. Its delayed Execute type effect can act as both a boon and bane for Death Knight players, and thus requires skill and practice to master.

Non-Specialization Abilities

Name	Level	Description
Parry	1*	Gives a chance to parry enemy melee attacks.
Blood Boil	55	Deals Shadow damage to all enemies within 10 yards, and spreads your existing diseases from your target to all other enemies hit.
Death Coil	55	Fires a blast of unholy energy at the target, causing Shadow damage to an enemy or healing an Undead ally.
Death Gate	55	Opens a gate, which the Death Knight can use to return to Ebon Hold.Using a Death Gate while in Ebon Hold will return the Death Knight back to near their departure point.
Death Grip	55	Harnesses the energy that surrounds and binds all matter, drawing the target toward the Death Knight and forcing the enemy to attack the Death Knight for 3 sec.
Frost Presence	55	Strengthens you with the presence of Frost, increasing Runic Power generation by 20%, and reducing the duration of effects that remove control of your character by 20%.Activating a new Presence will cancel this one and consume any stored Runic Power.
Icy Touch	55	Chills the target for Frost damage and infects them with Frost Fever.Frost Fever is a disease that deals Frost damage every 3 sec for 30 sec.
Plague Strike	55	A vicious strike that deals Physical damage and infects the target with Blood Plague.Blood Plague is a disease that deals Shadow damage every 3 sec for 30 sec.
Runeforging	55	Allows the Death Knight to emblazon their weapon with Runes.
Death Strike	56	Focuses dark power into a strike that deals Physical damage and heals you based on Attack Power.
Blood Presence	57	You assume the presence of Blood, increasing Stamina, base armor and reducing damage taken. Threat generation is significantly increased.Activating a new Presence will cancel this one and consume any stored Runic Power.
Mind Freeze	57	Smash the target’s mind with cold, interrupting spellcasting and preventing any spell in that school from being cast for 4 sec.
Chains of Ice	58	Shackles the target with frozen chains, reducing movement speed by 60% for 8 seconds, and infecting the target with Frost Fever.
Strangulate	58	Shadowy tendrils constrict an enemy’s throat, silencing them for 5 seconds.
Death and Decay	60	Corrupts the ground targeted by the Death Knight, causing Shadow damage over 10 sec to targets within the area.
On a Pale Horse	61	You become as hard to stop as death itself. The duration of movement-slowing effects used against you is reduced by 30%, and your mounted speed is increased by 20%.
Icebound Fortitude	62	The Death Knight freezes their blood to become immune to Stun effects and reduce all damage taken by 20% for 8 seconds.
Unholy Presence	64	You are infused with Unholy Fury, increasing haste by 10%, and movement speed by 15%.Activating a new Presence will cancel this one and consume any stored Runic Power.
Horn of Winter	65	The Death Knight blows the Horn of Winter, increasing attack power of all party and raid members within 100 yards by 10% for 1 hour.
Path of Frost	66	Activates a freezing aura for 10 min that creates ice beneath your feet, allowing party or raid members within 50 yards to walk on water. Useable while mounted, but being attacked or damaged will cancel the effect.
Anti-Magic Shell	68	Surrounds the Death Knight in an Anti-Magic Shell for 5 sec, absorbing 75% of all magical damage and preventing application of harmful magical effects. Damage absorbed generates Runic Power.
Control Undead	69	Dominates the target undead creature, forcing it to do your bidding. While controlled, the undead minion’s haste is reduced by 30%.Lasts up to 5 min.
Raise Ally	72	Pours dark energy into a dead target, reuniting spirit and body to allow the target to reenter battle with 60% health and 20% mana.
Death Heal	75	This is a passive ability that acts as a single button for all of your Level 75 talents. It allows you to switch between these talents without needing to rebind each ability every time you switch.
Empower Rune Weapon	76	Empower your rune weapon, immediately activating all your runes and generating 25 Runic Power.
Army of the Dead	80	Summons a legion of Ghouls over 4 sec who will fight for the Death Knight for 40 sec, swarming the area, taunting and fighting anything they can.
Outbreak	81	Instantly applies Blood Plague and Frost Fever to the target enemy.Blood Plague is a disease that deals Shadow damage every 3 sec for 30 sec.Frost Fever is a disease that deals Frost damage every 3 sec for 30 sec.
Dark Simulacrum	85	Places a dark ward on an enemy that persists for 8 sec, triggering when the enemy next spends mana on a spell, and allowing the Death Knight to unleash an exact duplicate of that spell. Against nonplayers, only absorbs some harmful spells.
Grip of Death	90	This is a passive ability that acts as a single button for all of your Level 90 talents. It allows you to switch between these talents without needing to rebind each ability every time you switch.

Talents

Talent	Description	Notes
Level 56 Tier (Diseases)
Plaguebearer	Death Coil and Frost Strike also infect your target, adding 4 seconds to the duration of Blood Plague and Frost Fever, and adding an addition stack to Necrotic Plague.	This talent essentially reduces how often you will either need to reapply Blood Plague or Frost Fever, or improves how quickly Necrotic Plague will ramp up in its stacks (making it deal slightly more overall damage). Decent for sustained DPS, and a recommended starter talent as it is fully passive.
Plague Leech	Consumes your Blood Plague and Frost Fever on the target to activate two random fully depleted Runes as Death Runes.	In Warlords of Draenor, many strikes no longer depend on the presence of diseases to deal full damage to their target. This makes Plague Leech the strongest option in terms of raw output and on-demand burst in this talent tier. This is countered by the need to plan its use carefully, as you also want to get diseases back up on the targets quickly.
Unholy Blight	Surrounds the Death Knight with a vile swarm of unholy insects for 10 sec, stinging all enemies within 10 yards, infecting them with Blood Plague and Frost Fever.	An AoE disease applier on a 90 second cooldown; Unholy Blight can work very well when paired with Necrotic Plague. Even when not talented into Necrotic Plague, it can be an excellent intermediate talent to take if a player is ready for something more engaging than Plaguebearer.
Level 57 Tier (Survival)
Purgatory	An unholy pact that prevents death when you sustain fatal damage, instead absorbing incoming healing equal to the amount of damage prevented, lasting 3 sec.If any healing absorption remains when this effect expires, you will die. This effect may only occur every 3 min.	A strong talent in situations where you’re frequently threatened with death. Purgatory will kill you if it is not healed out of, so be prepared to either use your self-healing abilities or have a nearby healer ready to immediately outheal the absorb placed by the debuff. Remember that this effect can only take place once every 3 minutes.
Anti-Magi Zone	Places an Anti-Magic Zone for 3 sec that reduces spell damage taken by party or raid members by 20%.	A powerful raid cooldown, Anti-Magic Zone can reduce large parts of damage taken by raid or party members when used strategically. Because it only lasts 3 seconds, it must be timed to coincide with heavy pulses or busts of magical damage, and is also best used when as many people as possible benefit from it.
Lichborne	Draw upon unholy energy to increase Leech, and make you immune to Charm, Fear, and Sleep for 10 sec.	In Warlords of Draenor, Lichborne now grants the Death Knight Leech when activated. Leech is a tertiary stat that converts a percentage of all damage done into healing. This makes Lichborne an excellent talent to use during periods when you require healing and want to help your healers out. The immunity to various Crowd Control effects that it grants can also be useful on a fight-by-fight basis.
Level 58 Tier (Movement)
Death’s Advance	You passively move 10% faster, and movement-impairing effects may not reduce you below 70% of normal movement speed.When activated, you gain 30% movement speed and may not be slowed below 100% of normal movement speed for 6 seconds.	A lovely talent for Death Knights! Death’s Advance has both an active and passive component, and provides bonuses in an area Death Knight traditionally lack in: Movement Speed. This is a very versatile talent that has equally good use in both PvP and PvE.
Chilblains	Victims of your Frost Fever are Chilled, reducing movement speed by 50% for 10 sec, and victims of your Chains of Ice are immobilized for 3 sec.	A strong talent for any situation that calls for kiting, or for slowing enemies. Remember that the actual duration of the slow is shorter than the duration of Frost Fever, and thus it must be refreshed by new applications of Frost Fever. The instant root granted by Chains of Ice can prove to also be very powerful in PvP situations.
Asphyxiate	Lifts an enemy target off the ground and crushes their throat with dark energy, stunning them for 5 sec. Functions as a silence if the target is immune to stuns.Replaces Strangulate.	This ability is an improved version of Strangulate. Because it now contains a stun component, it is equally useful against both melee and caster mobs. In arenas, it can prove invaluable against single targets, while burning down their team members.
Level 60 Tier (Rune Regeneration)
Blood Tap	Every 15 Runic Power you spend will generate a Blood Charge. Max 12 charges.Blood Tap consumes 5 Blood Charges to activate a random fully-depleted rune as a Death Rune.	This is the most “active” of the Rune Regeneration talents. Blood Tap is an actual ability that mandates consistently monitoring Blood Charges and knowing when to use them. To balance this, it also offers the best control and consistency out of any of the Rune Regeneration talents, and also generates Death Runes.
Runic Empowerment	When you spend Runic Power, you have a 1.50% chance per Runic Power spent to activate a random fully-depleted rune.	A more passive form of Rune Regeneration, Runic Empowerment has the highest theoretical rate of Rune Return. Because it is more passive compared to Blood Tap, it will replenish any type of Rune instead of generating Death Runes.
Runic Corruption	When you spend Runic Power, you have a 1.50% chance per Runic Power spent to increase your rune regeneration rate by 100% for 3 seconds.	The most passive form of Rune Regeneration by far, Runic Corruption simply speeds up existing Rune Regeneration when it procs. It is highly recommended for beginners to the class, as it requires the least amount of attention and also disrupts play flow the least.
Level 75 Tier (Self Healing)
Death Pact	Heals the Death Knight for 50% of their maximum health, and absorbs incoming healing equal to 25% of your maximum health for 15 seconds.	An incredible burst heal, Death Pact can save lives in clutch situations, especially when paired with a talent like Purgatory. The debuff it applies will need to be healed out of before you can benefit from further healing, but it more than earns its value for the size of the heal it delivers.
Conversion	Converts Runic Power to health, restoring 2% of maximum health per 1 second. Lasts until canceled or Runic Power is exhausted.	This ability lasts until cancelled, which means that it must be monitored. Each time it ticks, it consumes Runic Power according to varying costs that are determined by what specialization the Death Knight is in at the time. Good for consistent healing in arena-type situations. Note that the Runic Power spent can and will trigger Rune Regeneration.
Death Siphon	Deals Shadowfrost damage to an enemy, healing the Death Knight for a percentage of damage dealt.	As a ranged attack, Death Siphon offers strong potential for Death Knights that take it. The Death Rune cost means that it isn’t as easily useable as some of its counterparts, but this is understandable for a ranged attack that both deals damage and heals.
Level 90 Tier (Control)
Desecrated Ground	Corrupts the ground in an 8-yard radius beneath the Death Knight for 10 seconds. While standing in this corruption, the Death Knight is immune to roots, snares, and effects that cause loss of control. This ability instantly removes such effects when activated.	A CC breaker, Desecrated Ground is incredible for any form of PvP. In PvE, it also has niche uses on encounters where stuns, disorient effects, and slows might otherwise hamper your ability to attack the target.
Remorseless Winter	Surrounds the Death Knight with a swirling tempest of frigid air for 8 sec, chilling enemies within 8 yards every 1 second. Each pulse reduces targets’ movement speed by 15% for 3 seconds, stacking up to 5 times. Upon receiving a fifth application, an enemy will be stunned for 6 seconds.	An AoE stun, Remorseless Winter can change the tide of otherwise hopeless battles, especially as targets stunned by it can continue to be damaged with impunity for the duration of the stun. On the flipside, it also has a fairly lengthy ramp up. Note that any mob immune to the slow component of Remorseless Winter will NOT be stunned.
Gorefiend’s Grasp	Shadowy tendrils coil around all enemies within 20 yards of a target (hostile or friendly), pulling them to the target’s location.	One of the most unique and powerful cooldowns in the game. Gorefiend’s Grasp allows for instant repositioning of multiple hostile targets according to the Death Knight’s preference. This can be invaluable for multiple forms of PvE, and is something no other class can bring. The ability only affects 4 players at a time in PvP, but is still quite potent.
Level 100 Tier (Damage)
Breath of Sindragosa	Continuously deals Shadowfrost damage every second to enemies in a cone in front of you within 12 yards, and affects them with Mark of Sindragosa for 6 seconds. You will continue breathing until canceled or Runic Power is exhausted. Mark of Sindragosa causes you to be healed for 10% of spell damage dealt by afflicted enemies.	The “cooldown” of this tier, Breath of Sindragosa adds a new ability rather than replacing an existing one. It deals high burst damage upfront, but is difficult to maintain with its steep Runic Power cost. It is thus ideally utilized after pooling up Runic Power and faced with multiple enemies. Remember that the cone shape means it must be aimed!
Defile	Defiles the ground targeted by the Death Knight. Every 1 second, if there are any enemies standing in the Defile, it deals Shadowfrost damage to them, and grows in radius and damage by 2.5%. Enemies standing in your Defile deal 10% less damage to you. Replaces Death and Decay.	A direct replacement for Death and Decay. Defile is a semi-rotational ability, as making the most use out of it will mean using it off cooldown. It is best aligned with AoE packs as well, of course. The growth effect of the ability can be quite useful if your targets are spread out.
Necrotic Plague	A powerful disease that deals Shadowfrost damage per stack every 2 sec for 30 seconds. Each time it deals damage, it gains 1 stack, and infects another nearby enemy within 8 yards if possible. You gain 2 Runic Power whenever a target infected with Necrotic Plague attempts to attack you. Replaces Blood Plague and Frost Fever, and is applied by any ability which applied either. This effect cannot be refreshed; it gains 1 stack instead.	Necrotic Plague directly replaces both Blood Plague and Frost Fever, but deals enough damage over the course of its duration to be a gain over the loss of both. Its jump effect is only active if targets are within 30 yards of the Death Knight, but it can also be spread with Pestilence like Blood Plague or Frost Fever. Despite seeming to be the most passive of the Level 100 talents, it has the potential to dramatically affect rotations for specs that take it, and is very powerful for sustained damage.

UNHOLY

The Unholy Death Knight is a melee specialization DPS that utilizes Two-Handed weapons, making use of powerful diseases and undead minions as part of their arsenal. Unholy Death Knights are the only Death Knight specialization capable of maintaining a permanent pet, in the form of the ghoul. They are also capable of further empowering the ghoul with shadow magic, and summoning Gargoyle minions to bombard enemies with bursts of Plague damage.

Specialization Abilities

Ability	Level	Description
Ebon Plaguebringer	10*	Increases the damage your diseases deal by 60% and causes your Plague Strike to also apply Frost Fever.
Reaping	10*	Whenever you hit with Festering or Icy Touch, the Runes spent will become Death Runes when they activate. Death Runes count as a Blood, Frost, or Unholy Rune.
Raise Dead	56	Raises a ghoul to fight by your side. You can have a maximum of one ghoul at a time.
Scourge Strike	58	An unholy strike that deals Physical and Shadow damage.
Shadow Infusion	60	Your successful Death Coils empower your active Ghoul, increasing its damage dealt by 10% for 30 sec. Stacks up to 5 times.
Unholy Aura	60	Increases the haste of all party and raid members within 100 yards by 5%, and their Versatility by 3%.
Festering Strike	62	Deals Physical damage and increases the duration of your Blood Plague, Frost Fever, and Chains of Ice effects on the target by up to 6 sec. Requires Melee Weapon.
Sudden Doom	64	Unholy Presence grants your main-hand autoattacks a chance to make your next Death Coil cost no Runic Power.
Dark Transformation	70	Consume 5 charges of Shadow Infusion on your Ghoul to transform it into a powerful undead monstrosity for 30 sec. The Ghoul’s abilities are empowered and take on new functions while the transformation is active.
Summon Gargoyle	74	A Gargoyle flies into the area and bombards the target for 40 sec.
Mastery: Dreadblade	80	Increases all Shadow damage done by 20%.
Soul Reaper	87	Strikes an enemy for Physical damage and afflicts the target with Soul Reaper. After 5 sec, if the target is below 35% health, this effect will deal additional Shadowfrost damage. If the enemy dies before this effect triggers, the Death Knight gains 50% haste for 5 sec.
Necrosis	90	You gain 5% more of the Multistrike stat from all sources.Your Scourge Strike, Festering Strike, Plague Strike, Soul Reaper, and Pestilence multistrikes deal additional Shadow damage.

Draenor Perks

Draenor Perks are a special type of bonus unlocked for players over the course of leveling from 90-100. They vary according to specialization, and usually add some improvement or enhancement to existing spec mechanics. Different specs will unlock different perks in a random order (meaning that two players leveling with the same specialization could attain different perks at different levels), but by the time a player reaches Level 100 they will have successfully unlocked every perk.

Perk	Description
Empowered Gargoyle	Increases the duration of Summon Gargoyle by 10 sec.
Enhanced Dark Transformation	Dark Transformation no longer costs any Runes.
Enhanced Fallen Crusader	Rune of the Fallen Crusader heals for an additional amount.
Improved Soul Reaper	Your Soul Reaper ability now deals additional Shadow damage to targets below 45% instead of below 35%.

Rotation

Use Outbreak or Plague Strike to apply Blood Plague/Frost Fever.
Spend Unholy or Death Runes on Scourge Strike if you don’t need to refresh diseases.
Spend Blood and Frost Runes on Festering Strike.
Use Death Coil whenever you have Runic Power
Activate Dark Transformation whenever your Death Coil has accumulated 5 charges of Shadow Infusion.
Use Unholy or Death Runes on Soul Reaper off cooldown whenever a target is below 45% health.
Use your Gargoyle cooldown on high health targets and tough bosses.

Group Play

In situations where you face multiple enemies, use Blood Boil to spread diseases and deal damage to enemies. Also use Death and Decay to further damage them.

Your ghoul is both a blessing and a curse in groups—it will attack whatever you tell it to, but can also have a tendency to unwittingly pull patrolling mobs you are trying to bypass.

Remember to make liberal use of Anti-Magic Shell and Icebound Fortitude in any situation where you are taking damage—your healers will thank you for it!

Your Raise Ally ability can resurrect dead allies while in combat. This is invaluable utility that can potentially save your group from wiping, so be sure to use it if needed!

Group Buffs

All Death Knights provide the 10% Attack Power buff with Horn of Winter. In Warlords of Draenor, Unholy Aura provides 5% Haste to all group/raid members, and also provides 3% of the Versatility stat to group/raid members.

Preparing for High-End Content

When preparing for raids, make sure that your gems, enchants, and consumables such as potions/food all reflect the stat that you wish to stack the most. For Unholy Death Knights, this stat is Multistrike, followed closely by Mastery. These stats will contribute the most towards your damage, and are what you will seek on pieces of gear as well.

In Warlords of Draenor, accuracy stats such as Hit/Expertise are gone, and so is the ability to gem primary stats such as strength. This makes gearing much simpler in terms of finding items that contribute to your DPS. Remember that even if an item does not have either of these two stats, it can still be an upgrade if it has a higher item level or other useful properties such as extra gem sockets or tertiary stats.

FROST

The Frost Death Knight is a melee specialization DPS with a heavy emphasis on massive bursts of damage over short periods of time. Frost Death Knights rely on rapid weapon strikes and blasts of the icy magic to decimate their foes. They are capable of utilizing both Two-Handed weapons and dual wielding One-Handed weapons. Quite notably, their choice of weapons also influences their playstyle: Two-handed and dual-wielding Frost make use of the same core abilities, but utilize different rotations and gearing methods from one another.