Defense

Every knight and monster carries some amount of defense against each damage type. Defense reduces the amount of damage received in an attack. For large attacks, the net damage incurred by the target is simply the gross damage inflicted by the attacker, minus the defense of the target. For smaller attacks, the relationship between net and gross damage is more complicated and not yet completely understood by the players of Spiral Knights.

Knight Defense

A knight's defenses are primarily determined by his (or her) armor. Based on measurements of 5-star armors, in Lockdown at depth 25, it seems that armor can provide five distinct levels of defense:

• "Base'" defense is the lowest amount — for example, the piercing defense on Skolver Coat. A full set (both pieces) of base defense armor has been measured at 125 defense points.
• "Class" defense is the second most common amount of defense — for example, the normal defense on Skolver Coat. A full set of class armor has been measured at 142.
• "Special" defense is seen on defensive armor sets — for example, the piercing defense on Royal Jelly Mail. A full set has been measured at 150.
• "Plate" defense can be seen in the normal defense of Volcanic Plate Mail, for example. It has been measured at 201 for a full set.
• "Heavy plate" defense can be found only on the Ancient Plate Mail/Helm. It has been measured at 301 for a full set.

The numbers are different for other depths and other star rankings, but the ratios remain representative. In addition to armor, there are several other sources of defense for knights:

• 5-star defense trinkets have been measured at 32 for a pair of trinkets at depth 25.
• Defense from unique variants have been measured at 52 for a double max at depth 25.
• Battle sprite perks are equal to UVs.

In Lockdown, all knights have a minimum amount of defense for each damage type. Defenses below this amount gets increased to said limit. For Tier 3 Lockdown, this is around 100 defense. For Tier 2, it's around 42.

Monster Defense

Monsters have a fixed amount of defense depending on depth. Neutral defense will always be double of weak defense, but it can vary on a depth depending on buffs and debuffs from poison, yesmen, danger rooms, and similar buffs. It is not yet known how much strong defense monsters have, nor is it certain if strong defense utilizes the same formula as weak and neutral.

Here are some measured defense numbers. They are not exact, as the actual amounts are not integers. Instead, they are displayed as minimum for the first depth and a maximum for the last depth of a stratum.

Some monsters are exceptional. Oilers that are lit on fire get their elemental defense increased to strong defense. Lord Vanaduke has his own amount of defenses, not being tied to any family. These values are 150 piercing, 180 normal, 200 elemental and 200 shadow. His mask has 150 normal, 200 elemental, shadow and piercing defense.

Calculating Damage

When the gross damage inflicted in an attack is greater than twice the defense of the target, the net damage incurred by the target is simply their difference:

net damage = gross damage - defense.

The relationship is more complicated when gross damage is less than twice the defense. We can be certain that

net damage < gross damage / 2,

but we do not understand much more than that. The practical effect of defense diminishes as the defense approaches gross damage.

For example, suppose that a beast has 150 normal defense, 75 piercing defense, and 150 shadow defense. You have three swords: normal, piecing, and normal+shadow.

• Your normal sword does 400 gross damage, for net damage of 400 - 150 = 250 against the beast.
• Your piercing sword does 400 gross damage, for net damage of 400 - 75 = 325.
• Your normal+shadow sword does 275 damage of each type, for net damage of (275 - 150) + (275 - 150) = 125 + 125 = 250.

References

This article is a synthesis of various player research projects, including:

• guild advanced training hall measurements
• damage measurements against lost souls, which have no defense
• Lockdown defense measurements
• thread about the creation of this page, which holds further links