Noble Phantasm

A Noble Phantasm or NP for short, is a Servant's unique special attack during battle. These act like normal Command Cards, but have additional powerful abilities that have various effects in battle, like area-of-effect damage, inflicting Status Effects, healing, among others.

Noble Phantasms use the NP Gauge, located below the Servant's Health bar. Noble Phantasms may only be used when this gauge reaches 100% or higher. The gauge fills up by attacking enemies with normal Command Cards, getting hit by enemies, or using various Active Skills. It also fills up by equipping various Craft Essences that affect NP, like "Starting NP", "NP Acquisition", and "NP Regeneration".

Once the NP gauge is filled up, the Servant's NP gauge glows to indicate that the Noble Phantasm is ready to be used. At the Command Card selection screen, the Noble Phantasm cards appears above the normal Command Cards, but will completely empty the Servant's NP gauge upon activation, and will require refilling before it is available again.

Note that the NP Charge it actually activates under is based on 100s intervals and is downscaled (e.g. 163% NP Gauge emptied results in only activating the Noble Phantasm at 100% Charge, not 200%).

Characteristics
Each Noble Phantasm has a Rank, Level, and Type.

The Rank of a Noble Phantasm denotes its overall effectiveness. When the Rank of a NP increases, its primary effect is amplified. The Rank of a Servant's NP can only be increased by completing that Servant's personal Interlude, noting that not all Servants may have Interludes.

The Level of a Noble Phantasm directly affects its primary effect's potency and may increase the Servant's maximum NP Gauge. Each Servant's NP has a maximum level of 5, which can only be increased by fusing the same Servant card to it. Upon reaching Level 2, the NP Gauge's maximum increases to 200%. Likewise, reaching Level 5 increases the gauge to 300%, currently the highest possible maximum.

The Type of a Noble Phantasm indicates what kind of Command Card it behaves as.

Effects
Each Noble Phantasm has at least 2 Effects. The Primary Effect and the Secondary Effect.

The Primary Effect of a Noble Phantasm is only directly affected by its Level and Rank.

The Secondary Effect of a Noble Phantasm is increased by the amount of NP Gauge it utilizes.

An example is Artoria's Noble Phantasm: Excalibur. It is a Rank A, Buster Type Noble Phantasm that has a Primary Effect of dealing damage to all enemies, and a Secondary Effect of Recharging her NP Gauge by a certain amount.

Overcharge
When multiple Noble Phantasms are used in the same turn, the later Noble Phantasms are Overcharged. Overcharge allows a Noble Phantasm to exceed the current maximum NP gauge amount. Each Noble Phantasm activation gets +100% NP Charge for each Noble Phantasm activated before it this turn. This value is fixed - it does not matter how high your Servant's NP gauge is, it can only be Overcharged by 100% per previous Noble Phantasm used. The maximum amount of NP charge at any condition or in any combination is 500%.

During the Command Phase, if you choose 2 Noble Phantasms in a row, the message Noble Phantasm Chain Bonus Activated! (宝具チェインボーナス獲得!) will appear with a sound effect to alert you that your Noble Phantasms will be Overcharged.

If your three Servants all have a maximum of 100% NP gauge and you queue up all the Noble Phantasms in a row, the 1st NP will have 100%, the 2nd will have 200%, and the last will have 300%.

If you activate your Noble Phantasms in the order of 200%, 100%, 200%, the initial NP has 200% Charge, the second gets (100+100 = 200%) Charge, and the last one will have (200+100+100 = 400%) Charge.

Overcharge only affects the secondary effect of a Noble Phantasm. Overcharge does NOT directly increase the damage dealt by the Noble Phantasm! You can indirectly increase damage by, for example, overcharging a NP that afflicts Defense Down or stated to be so like Increase NP Damage, but the base damage of any given NP is going to be the same whether it has 100% or 500% charge.

Using Artoria Pendragon's Noble Phantasm as an example:

If you cast Excalibur by itself with no other NPs, it will refund her NP gauge by 20% at 100% charge, 27.5% at 200% charge, and 35% at 300% charge. However, if you have 2 other Servants with NPs ready, the amount refunded will depend on when you cast Excalibur and how much charge Artoria has: