Game Mechanics

General

• Oskills are skills without a class-specific modifier, such as "+X to Battle Orders" or "+X to Zeal", and are limited to +3 from all sources when used on the class the skill belongs to. For example, the Ferocity runeword on a paladin will provide +3 to Zeal rather than the listed +12 to +14. This is a regular D2 mechanic.

Melee Splash

Melee splash is an instant AoE, with no Next Hit Delay, that damages all enemies 360° around the target. The main target does not take splash damage.

An attack's splash damage is rolled once and applied according to each enemy's resistances, but effects that have a chance of applying (Crushing Blow, Open Wounds) are rolled individually for each enemy hit in melee splash.

These are included in the splash:

• Skill damage
• Converted damage (e.g. Concentrate)
• Normal attack damage (the values you see when you select the basic attack as your skill)
• Elemental and physical damage from charms and gear
• Critical Strike and Deadly Strike (still only applies to the physical damage)
• Life and Mana leech (reduced by 1/2, and still only applies to the physical portion of the attack)
• Crushing Blow
• Open Wounds

These are not included in the splash:

• Missile damage (such as the Nova portion of Power Strike)
• Stun
• Knockback
• Any other on-hit effects

Melee Splash Examples

Let's take a look at a couple of examples. First, let's take an Amazon:

• Lightning Strike for 1-10000 lightning damage and 1-10000 chain lightning damage
• Normal attack damage of 1000-5000 (900-4900 of that is physical)

The total splash damage would be 1001-15000 damage.

And if they crit then the splash damage would be 1451-17450.

The 1-10000 damage from the Chain Lightning is not applied.

What about a Barbarian:

• Concentrate (300% ED, 50% conversion)
• Normal attack damage of 1000-5000 (900-4900 of that is physical)

First the physical portion of the normal attack damage is boosted by Concentrate's ED% bonus: 900-4900 becomes ~1800-9800

Then 50% of the physical damage is converted to magic

The total splash damage would be 1900-9900 [100-100 elemental damage + 900-4900 physical + 900-4900 magic]

And if they crit then the splash damage would be 2800-14800

Splash Radius

The base player melee splash radius is 5 tiles (3.33 yards) but this can be extended by certain skills and items. The splash radius will increase by 1 tile (0.66 yards) for every 20% "increased splash radius" gained.

Increased Splash Radius	0	20	40	60
Tiles	5	6	7	8
Radius (yards)	3.33	4	4.66	5.33

There are also a handful of other things that have melee splash. These are all static and cannot be increased.

• "Splashing" map modifier: melee splash radius is 5 tiles (3.33 yards)
• Golems: melee splash radius is 4 tiles (2.66 yards)
• Skeletons: melee splash radius is 3 tiles (2 yards)
• Wolves: melee splash radius is 2 tiles (1.33 yards)

Melee splash and ranged weapons

There are a few gloves (The Hand of Broc, Bloodfist, and Steelrend) that have melee splash on them and they can be used to give ranged weapons, like bows and crossbows, melee splash.

This allows shapeshifters to use a ranged weapon in place of a melee weapon, while still gaining the benefits of melee splash.

This does not mean that ranged attacks (i.e. shooting with a bow) will have splash damage. Melee splash is always limited to melee attacks.

Critical Damage

Critical damage has been rebalanced to improve itemization by making the power of Deadly Strike more comparable to other item stats, and other sources of crit chance have been changed in the same way. Skills have been rebalanced with additional damage to compensate for this difference.

Each source of crit chance now caps at 75% instead of 100% and crits multiply physical attack damage by 1.5x instead of by 2x.

There are 3 different sources of crit chance:

• Deadly Strike: items, Blessed Aim
• Critical Strike: Critical Strike, Hunger, Joust
• Weapon Mastery: General Mastery, Polearm and Spear Mastery, Throwing Mastery, Claw and Dagger Mastery, Javelin and Spear Mastery

Total Crit Chance: 1 - ((1 - DS) * (1 - CS) * (1 - WM)) (rounded down to the nearest percent)

As an example, consider an Amazon with:

• 50% DS crit from gear
• 50% CS crit from Critical Strike

1 - ((1 - 0.50) * (1 - 0.50) * (1 - 0)) = 75% chance to crit

Another example:

• 40% DS crit from gear
• 65% CS crit from Critical Strike
• 30% WM crit from Javelin and Spear Mastery

1 - ((1 - 0.40) * (1 - 0.65) * (1 - 0.30)) = 85% chance to crit

The theoretical maximum total crit chance is 95% (75% DS, 75% CS, 35% WM)

Life and Mana Steal

Leech Reductions

Attack leech reduction

• Melee Splash: 1/2 [Life/Mana]
• Ranged Attacks: 1/2 [Life/Mana]

Skill leech reduction

• Blade Shield: 1/2 [Life/Mana]
• Leap Attack: 1/3 [Life]

Difficulty leech reduction

• Normal: N/A
• Nightmare: 1/2 [Life/Mana]
• Hell: 1/3 [Life/Mana]

Zone leech reduction

• PvP maps: set leech to 0% [Life/Mana]

Leech Formula

leeched life/mana = [[[leech * attack_reduction * skill_reduction] * 64 * difficulty_reduction] * physical_damage * drain_effectiveness / 64 / 100]

Note: Bracketed values are rounded down

As an example, consider a Barbarian with 7% Life leech, using Leap Attack (5k damage) against The Cow Queen:

• [[[7 * 1/2 * 1/3] * 64 * 1/3] * 5000 * 0.2 / 64 / 100]
• [[1 * 64 * 1/3] * 5000 * 0.2 / 64 / 100]
• [21 * 5000 * 0.2 / 64 / 100] = 3hp leeched

Another example, consider a Paladin with 9% Life leech, using Zeal (3k damage) against a Death Beatle:

• [[[9 * 1/2] * 64 * 1/3] * 3000 * 0.5 / 64 / 100]
• [[4 * 64 * 1/3] * 3000 * 0.5 / 64 / 100]
• [85 * 3000 * 0.5 / 64 / 100] = 19hp leeched

Crushing Blow

Crushing Blow reduces the target's life by a fraction of their current life, so it's more effective against targets with lots of life and becomes less effective as they lose life. Attacks can have up to 100% chance to cause a Crushing Blow - any extra will have no effect.

• Crushing Blow now has greater diminishing returns against bosses (act bosses, map bosses, ubers)
• The melee life reduction is now the same as the ranged reduction

Target	Melee (PD2)	Ranged (PD2)	Melee (LoD)	Ranged (LoD)
Most Targets	1/8	1/8	1/4	1/8
Super Uniques	1/8	1/8	1/8	1/16
Bosses	1/80**	1/80**	1/8	1/16
Players and Mercenaries	1/10	1/10	1/10	1/20

* "Most Targets" refers to pets as well as normal, minion, Champion, and Unique monsters

** Affected by diminishing returns: 80 + pow(missing hp%, 2)

Also see: Vanilla Info about Crushing Blow

Open Wounds

• Open Wounds deals physical damage over time
  • The damage depends on the level of the character who applies it (shown below for all levels)
  • The damage is now affected by "+X Open Wounds Damage per Second" which is a new attribute that often accompanies "X% Chance of Open Wounds"
  • The damage is now affected by Physical Damage Reduction (e.g. Battle Cry, Amplify Damage, Defiance, etc)
  • The damage is not affected by other damage modifiers
• Open Wounds is now also applied by "Attacker Takes Damage of X" as well as attacks
• Open Wounds now lasts 5 seconds (was 8 seconds) and now stacks up to 3 times per target
• Open Wounds now has a ¼ penalty against mercenaries and pets
• Open Wounds no longer has a ½ penalty against stronger enemies (champions, uniques, super uniques, bosses, prime evils)

Open Wounds Damage per Second

Character Level	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25
Damage per Second	3	4	5	6	7	8	9	10	10	11	12	13	14	15	16	17	19	21	23	25	26	28	30	32	33
Character Level	26	27	28	29	30	31	32	33	34	35	36	37	38	39	40	41	42	43	44	45	46	47	48	49	50
Damage per Second	35	37	39	40	42	45	47	50	53	55	58	61	63	66	68	71	74	76	79	82	85	89	92	96	99
Character Level	51	52	53	54	55	56	57	58	59	60	61	62	63	64	65	66	67	68	69	70	71	72	73	74	75
Damage per Second	103	106	110	113	117	120	124	127	131	134	139	143	148	152	156	161	165	170	174	178	183	187	191	196	200
Character Level	76	77	78	79	80	81	82	83	84	85	86	87	88	89	90	91	92	93	94	95	96	97	98	99
Damage per Second	205	209	213	218	222	227	231	235	240	244	249	253	257	262	266	271	275	279	284	288	293	297	301	306

Also see: Vanilla Info about Open Wounds, Deep Wounds

Reducing Resistances

Resistances are now reduced at 1/2 effectiveness (was 1/5 effectiveness) when those resistances are above 99% (immunes) or below 0%.

This effectiveness penalty only applies to effects caused by players and pets. Negative resistances caused by monsters (e.g. Conviction, Amplify Damage) are always applied at full effectiveness.

Breaking Immunes

These effects "reduce" or "lower" enemy resistances and will break immunities. They all apply an effect to the enemy which persists and reduces their resistance while it is active, which allows all players to benefit:

• Battle Cry (Physical)
• Amplify Damage (Physical)
• Decrepify (Physical)
• Lower Resist (Fire/Cold/Lightning/Poison)
• Conviction (Fire/Cold/Lightning)
• Sanctuary (Magic)
• Poison Creeper (Poison)
• Arctic Blast (Cold)
• Inferno (Fire)
• Static Field (Lightning)

These effects "penetrate" or "pierce" enemy resistances and will not break immunities. They only benefit the character who uses them:

• -% to enemy resistance from items or skills (e.g. Kira's Guardian, Rainbow Facet, Cold Mastery, Fire Mastery, Poison Strike, Berserk)

Effectiveness vs Immunes

All effects which "reduce" resistances (those that can break immunities) are applied simultaneously against immune enemies, rather than sequentially. This means that even if multiple immunity-breaking skills are used and one of them would be powerful enough to break an immunity alone, they all still apply at 1/2 effectiveness.

As an example let's take an enemy with 110% fire resistance, and apply both Lower Resist and Conviction each at levels where they have "Enemy Resistances -30%":

• -30 / 2 = -15  [apply the 1/2 penalty to Lower Resist]
• -30 / 2 = -15  [apply the 1/2 penalty to Conviction]
• 110 - 15 - 15 = 80  [take the final -resist values and apply them to the enemy]

Effects which "penetrate" resistances rather than "reduce" them (e.g. Rainbow Facet, Cold Mastery) will be applied afterward and will work at full effectiveness against enemies that have had their immunities broken.

Effectiveness vs Negative Resistance

When taking an enemy below 0% resistance, the effectiveness penalty only applies to whatever portion becomes negative. Everything applies at full effectiveness and then afterward, if the enemy's resistance is negative, it gets halved.

As an example let's take an enemy with 25% cold resistance, and apply Lower Resist and Conviction from before as well as an extra "-12% to Enemy Cold Resistance":

• 25 - 30 = -5  [Lower Resist]
• -5 - 30 = -35  [Conviction]
• -35 - 12 = -47  [-Enemy Resist]
• -47 / 2 = -23  [apply the 1/2 penalty to get the final enemy cold resist]

Resists can be reduced as low as -100%

Item drop mechanics

Item drop Basics

Lets look at a high-level example of how the drop process works.

Mephisto is killed! What does the game do to determine your reward?

1. calculates the number of items to drop (max 6)
2. selects item types
3. selects item qualities
4. selects certain unique or set items (when applicable)
5. selects item properties (when applicable)

The number of players only affects item #1, the number of potential drops. It has no affect on the quality of the items that drop (this is where magic find comes into play). Now the question is, how does the number of players affect how many items drop?

Any time you do something that drops loot (opening a chest, killing a monster, etc.) the game selects from a list of treasure classes (TC) that will decide what kind of items will drop. Each TC has a list of items (or other TCs) that can drop, as well as a probability that that given item will drop. There is also a number of "picks" for each TC that decides how many potential items can drop. The last piece of the puzzle is "NoDrop", which is a probability that a pick will drop no items. NoDrop is the only parameter that player count affects.

There's a lot that goes into how the new NoDrop value is calculated when more players join the game, but the short version is: the higher the player count, the lower the NoDrop chance (potentially reaching 0 with enough players).

There are some TCs that start with NoDrop at 0. These are not affected by player count, since 0 is the lowest possible value.

What's different in PD2?

The baseline drop rate in PD2 is roughly equivalent to vanilla's p5/5 (5 partied players in a game) for solo play, and scales up per player until it's slightly above the equivalent of vanilla's p8/8 when there is a full game of 8 players. This means that overall NoDrop for all TCs is significantly lower, and it becomes easier to reach a NoDrop of 0 with fewer players.

You still get loot increases from more players like vanilla, but the difference between a solo player and a group of 8 is overall much smaller.

Rune TCs are also the same as in vanilla, so rune drop rates are the same. Miniscule differences may exist in some cases due to new valuable items such as Larzuk's Puzzlebox being able to drop.

How does PD2 compare to LoD?

It's hard to directly compare the two since there are hundreds of TCs, and PD2 has even more than LoD (mostly because of maps). But we can compare a TC from LoD to a TC from PD2 and see how the NoDrop chance has changed.

Let's look at the TCs called Swarm 2 (H), a worst case scenario, and Act 2 (H) H2H A, a common case used by many monsters. In these examples, the first number is the amount of players in the game and the second number is the amount of players in the party. So p3/2 means 3 players in the game but only 2 in your party. If you used the /players 8 command in single player that would be equivalent to p8/1.

Chance for NoDrop to be selected by the "pick" (i.e. the chance that no item drops):

Treasure Class	LoD	PD2
Swarm 2 (H)	p1/1, p2/1 = 83.33% p2/2, p3/1, p3/2, p4/1 = 69.14% p3/3, p4/2, p4/3, p5/1, p5/2, p6/1 = 57.63% p4/4, p5/3, p5/4, p6/2, p6/3, p7/1, p7/2, p8/1 = 47.92% p5/5, p6/4, p6/5, p7/3, p7/4, p8/2, p8/3 = 39.02% p6/6, p7/5, p7/6, p8/4, p8/5 = 32.43% p7/7, p8/6, p8/7 = 26.47% p8/8 = 21.88%	p1/1, p2/1 = 40.85% p2/2, p3/1, p3/2, p4/1 = 16.64% p3/3, p4/2, p4/3, p5/1, p5/2, p6/1 = 6.68% p4/4, p5/3, p5/4, p6/2, p6/3, p7/1, p7/2, p8/1 = 2.75% p5/5, p6/4, p6/5, p7/3, p7/4, p8/2, p8/3 = 0.99% p6/6, p7/5, p7/6, p8/4, p8/5 = 0.33% p7/7, p8/6, p8/7 = 0.17% p8/8 = 0%
Act 2 (H) H2H A	p1/1, p2/1 = 62.50% p2/2, p3/1, p3/2, p4/1 = 38.78% p3/3, p4/2, p4/3, p5/1, p5/2, p6/1 = 24.05% p4/4, p5/3, p5/4, p6/2, p6/3, p7/1, p7/2, p8/1 = 14.29% p5/5, p6/4, p6/5, p7/3, p7/4, p8/2, p8/3 = 9.09% p6/6, p7/5, p7/6, p8/4, p8/5 = 4.76% p7/7, p8/6, p8/7 = 3.23% p8/8 = 1.64%	p1/1, p2/1 = 9.52% p2/2, p3/1, p3/2, p4/1 = 0.88% p3/3, p4/2, p4/3, p5/1, p5/2, p6/1 = 0% p4/4, p5/3, p5/4, p6/2, p6/3, p7/1, p7/2, p8/1 = 0% p5/5, p6/4, p6/5, p7/3, p7/4, p8/2, p8/3 = 0% p6/6, p7/5, p7/6, p8/4, p8/5 = 0% p7/7, p8/6, p8/7 = 0% p8/8 = 0%

Key drop rates

Players	1	2	3	4	5	6	7	8
Blood Raven	11.55%	11.58%	11.58%	11.58%	11.58%	11.58%	11.58%	11.58%
Countess	9.45%	9.46%	9.46%	9.46%	9.46%	9.46%	9.46%	9.46%
Bloodwitch	11.55%	11.58%	11.58%	11.58%	11.58%	11.58%	11.58%	11.58%
Summoner	12.83%	12.88%	12.88%	12.88%	12.88%	12.88%	12.88%	12.88%
Izual	11.55%	11.58%	11.58%	11.58%	11.58%	11.58%	11.58%	11.58%
Nihlathak	12.00%	12.02%	12.02%	12.02%	12.02%	12.02%	12.02%	12.02%
Countess (LoD)	7.14%	9.08%	9.61%	9.80%	9.80%	9.80%	9.80%	9.80%
Summoner (LoD)	8.62%	11.61%	12.48%	12.80%	12.80%	12.80%	12.80%	12.80%
Nihlathak (LoD)	7.93%	10.41%	11.10%	11.35%	11.35%	11.35%	11.35%	11.35%