Armor

Armor

Armor reduces the amount of damage you take by a percentage, increasing with the number of armor you have as seen below. Each point of armor increases the amount of damage it effectively takes to kill you by 6.66% per point.

The Tooltip for the Damage Reduction from Armor rounds to the nearest whole %. However, the actual damage reduction the game uses does not round.

Damage reduction and Effective HP at different Values:

ArmorStat	0	1	2	3	4	5	6	7	8	9	10	15	30	45	60
Dmg Reduction (-%)	0	6	12	17	21	25	29	32	35	38	40	50	67	75	80
Effective HP Increase (+%)	0	6	14	20	27	33	41	47	54	61	67	100	200	300	400
HP Increase Difference (+%)	-	6	8	6	7	6	8	6	7	7	6	33	100	100	100

• For a more complete list of changes per stat point, see Formulas & Values below.

While the amount of reduced x% damage per point goes down. The value of each % damage reduced goes up. The first point of armor grants you 6% reduced damage taken. However, going from 9 to 10 armor only makes your damage reduction go up by 2% - From 38% to 40%.

These 2% are exactly as powerful as the first 6%. And the effect of armor is linear, each point is as valuable as the point before. To better understand this, lets take some examples.

If you go from 0% reduction to 10%, that 10% reduction means you take 10% less damage. But if you have 80% damage reduction and get +10%, so you have 90% damage reduction, that +10% increase just halved the amount of damage you take.

For example, if you have 100 Max HP, and 0 armor it takes 100 damage to kill you. But if you have 5 armor, you reduce the damage by 25%, so now it takes 100/0.75=133 damage to kill you.

The amount of theoretical damage it takes to kill you is called Effective HP.

Now if you have 15 Armor, you have 50% damage reduction, and that means your 100 max HP can now take 200 damage before dying. Three times the armor also means you can take three times the extra damage. And for every 100 Max HP you have, each 5 points of armor means you can take 33 damage before dying.

Said in another way, each point of armor increases your Effective HP by 6.66%.

If you have negative armor, the damage you take is instead increased by the percentage. So if you have -15 armor, where 15 armor would give 50% damage reduction, -15 armor means you takes 150% damage.

Negative armor, unlike positive amounts of armor, has diminishing returns. Going from 50% damage reduction to 75% (thats going from 15 to 30 armor) for positive armor means you halve the amount of damage you take from 50% to only taking 25%. But for negative armor, this means going from taking 150% to taking 175% damage, which just means you take a relative 16% more damage than before.

As a result, when you play Ghost, who starts with -100 armor, (taking 187% damage) it doesn't make a notable difference if you gain +10 or -10 additional armor. As it just changes the damage you take to between 186% to 188%

Items

Positive

These items increase your Armor.

Due to Item Tags, the Character(s) Bull, Golem, Knight, Masochist, Pacifist have a higher chance to find these items in the Shop.

Name	Rarity	Effects	Base Price	Limit	Unlocked By
Barricade	Tier 3	+3 Knockback +8 Armor while standing still. -5% Speed	75
Duct Tape	Tier 1	+1 Armor +1 Engineering -2 Max HP	20
Exoskeleton	Tier 4	+3 Armor +5% Crit Chance +5 Engineering +5% Speed -2 HP Regeneration -2% Life Steal	90
Helmet	Tier 1	+1 Armor -2% Speed	15
Leather Vest	Tier 2	+2 Armor +6% Dodge -3 Max HP	45
Medal	Tier 2	+3 Max HP +3% Damage +1 Armor +3% Speed -4% Crit Chance	55
Metal Plate	Tier 2	+2 Armor -3% Damage	40
Robot Arm	Tier 4	+3 Melee Damage at the end of a wave +3 Engineering at the end of a wave -1 Max HP at the end of a wave	100		Win a run with Engineer
Triangle of Power	Tier 3	+20% Damage +1 Armor -2% Damage until the end of the wave when you take damage	65
Warrior Helmet	Tier 3	+3 Armor +5 Max HP -5% Speed	80

Negative

These items decrease your Armor.

Name	Rarity	Effects	Base Price	Limit	Unlocked By
Big Arms	Tier 4	+12 Melee Damage +6 Ranged Damage +3 Knockback -3% Attack Speed -3% Speed	105		Win a run with Generalist
Gambling Token	Tier 2	+8% Dodge -1 Armor	50
Glass Cannon	Tier 3	+25% Damage -3 Armor	75
Gummy Berserker	Tier 1	+5% Attack Speed +25 Range -1 Armor	25
Jet Pack	Tier 4	+15% Speed +10% Dodge -5 Max HP -1 Armor	100
Night Goggles	Tier 4	+15% Crit Chance +50 Range -3 Max HP -1 Armor	95		Win a run with Ranger
Sunglasses	Tier 2	+10% Crit Chance -1 Armor	50
Wheelbarrow	Tier 2	-1 Armor +16 Harvesting	40

Mechanics

The Anvil can increase your Armor stat, but is not tagged as an Armor Item.

Name	Rarity	Effects	Base Price	Limit	Unlocked By	Tags
Anvil	Tier 4	A random weapon is upgraded when entering a shop. If you have no weapon to upgrade, you gain +2 Armor instead.	120	1	Win a run with Arms Dealer	None

Characters

These Characters start with different Armor, or have mechanics related to their Armor:

Positive Characters

Name	Stats	Unlocked By	Unlocks
Bull	+20 Max HP +15 HP Regeneration +10 Armor HP Regeneration modifications are increased by 50% You explode for 30 (300% 300% 300%) damage when you take damage This explosion has a 1.5x crit multiplier You can't equip weapons	Win a run in Danger 1	Gnome
Masochist	+5% Damage when you take damage until the end of the wave +10 Max HP +20 HP Regeneration +8 Armor -100% Damage	Win a run in Danger 3	Spiky Shield
Knight	+2 Melee Damage for every 1 Armor you have +3 Armor You can't equip ranged weapons You can only equip tier 2 weapons or above % Attack Speed modifications are reduced by 50% Harvesting modifications are reduced by 80%	Win a run in Danger 4	Plasma Sledgehammer

Negative Characters

Name	Stats	Unlocked By	Unlocks
Ghost	+10 Damage with Ethereal weapons +30% Dodge Dodge is capped at 90% -100 Armor	Reach +60% Dodge	Ritual
Speedy	+30% Speed +1 Melee Damage for every 2% Speed you have -100 Armor while standing still -3 Armor	Reach +50% Speed	Fin
Doctor	+200% Attack Speed with Medical weapons +5 HP Regeneration HP Regeneration modifications are increased by 100% +5 Harvesting -100% Attack Speed Armor modifications are reduced by 50%	Heal 200 HP in one wave	Medikit
Artificer	+175% Explosion Damage +4% Explosion Size for every 1 Elemental Damage you have +100% Damage with Tool weapons -100% Damage Armor modifications are reduced by 50%	Kill 15 Enemies with a single explosion	Explosive Shells

Weapons

These Weapons affect Armor:

Name	Class	Damage	Attack Speed	DPS	Crit Damage/Chance	Range	Knockback	Lifesteal	Special Effects	Base price	Unlocked by
Rock	Primitive, Blunt	20(100%) 35(100%) 50(100%) 70(100%)	1.68s 1.61s 1.53s 1.46s	11.9(59%)/s 21.7(62%)/s 32.7(65%)/s 47.9(68%)/s	x1.5 (10%) x1.5 (15%) x1.5 (20%) x1.5 (25%)	150 150 150 150	5 5 5 5	0 0 0 0	-/+1 Armor/+1 Armor, +2 Max HP/+2 Armor, +2 Max HP	10 22 45 91	Default

These Weapons use your Armor stat to deal more damage:

Name	Class	Damage	Attack Speed	DPS	Crit Damage/Chance	Range	Knockback	Lifesteal	Special Effects	Base price	Unlocked by
Spiky Shield	Medieval, Blunt	10(100%) 15(125%) 20(150%) 30(200%)	1.16s 1.16s 1.16s 1.01s	8.6(86%)/s 12.9(107%)/s 17.2(129%)/s 29.7(198%)/s	x2 (3%) x2 (3%) x2 (3%) x2 (3%)	150 150 150 150	20 20 20 20	0 0 0 0		15 31 61 122	Win a run with Masochist

Weapon Classes

These Weapon Classes affect Armor:

Class	Bonuses	Weapons
Blunt	(2)+1 Armor -2% Speed (3)+1 Armor +3 Max HP -4% Speed (4)+2 Armor +3 Max HP -6% Speed (5)+2 Armor +6 Max HP -8% Speed (6)+3 Armor +6 Max HP -10% Speed	Rock   Spiky Shield   Hammer
Ethereal	(2)+6% Dodge Chance -1 Armor (3)+12% Dodge Chance -2 Armor (4)+18% Dodge Chance -3 Armor (5)+24% Dodge Chance -4 Armor (6)+30% Dodge Chance -5 Armor	Ghost Axe   Ghost Flint   Ghost Scepter   Scythe
Medieval	(2)+1 Armor (3)+1 Armor, +3% Dodge (4)+2 Armor, +3% Dodge (5)+2 Armor, +6% Dodge (6)+3 Armor, +6% Dodge	Quarterstaff   Jousting Lance   Spiky Shield   Crossbow   Sword

Formulas & Values

The formula used by the game for calculating Armor's damage reduction value is:

 % Damage taken after armor  = 1 / ( 1 + ( ARMOR / 15 ) )
Tooltip for Damage Reduction % = ROUND( ( 1 - ( DmgReceived% ) ) * 100 )

It can be clearly seen here that it takes 15 armor to doubles your HP. And that the Tooltip rounds the number to the nearest %

This table shows various damage reduction values with different Armor stats.

For every 1 :

ArmorStat	0	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	26	27	28	29	30
Dmg Reduction (-%)	0	6	12	17	21	25	29	32	35	38	40	42	44	46	48	50	52	53	55	56	57	58	59	61	62	63	63	64	65	66	67
Effective HP Increase (+%)	0	6	14	20	27	33	41	47	54	61	67	72	79	85	92	100	108	113	122	127	133	138	144	156	163	170	170	178	186	194	203

For every 10 :

ArmorStat	10	20	30	40	50	60	70	80	90	100
Dmg Reduction (-%)	40	57	67	73	77	80	82	84	86	87
Effective HP Increase (+%)	67	133	203	270	335	400	456	525	614	669

For every 100 :

ArmorStat	100	200	300	400	500	...	1000
Dmg Reduction (-%)	87	93	95	96	97	...	99
Effective HP Increase (+%)	669	1329	1900	2400	3233	...	9900

Stats
Max HP	Melee Damage	Crit Chance	Dodge
HP Regeneration	Ranged Damage	Engineering	Speed
Life Steal	Elemental Damage	Range	Luck
Damage	Attack Speed	Armor	Harvesting