Grinding

Weapon grinding is the process of strengthening weapons, increasing their ATP/TP and PP by reasonable amounts.

All weapons start at 0, and can be ground up to an initial maximum level of 10. The downside to grinding is that, if grinding fails, the weapon will lose one or two of its grinds, and its maximum potential grind will decrease by one. This happens each time a weapon breaks.

How to Grind

In order to grind, you must first have Grinders with which to grind the weapon. The grinder must be of equal or greater Weapon Rank compared to the weapon you wish to grind (e.g. you can grind a C-rank weapon with any grade of grinder, while S-rank weapons can only be ground using S-rank grinders). Different Grinders of the same Rank may be of different quality (represented by a number e.g. +1 or +4), thus affecting the success rate of the grinding. If you have the grinders, you must go to the Grinding Shop of the manufacturer of the weapon you wish to grind. For example, G.R.M. weapons can be ground at the G.R.M. Shop in Holtes City west on Parum, and Yohmei weapons are ground at the Yohmei Shop in Ohtoku City on Neudaiz. Kubara weapons need to be taken to the Junk Shop on the second floor of the GUARDIANS Colony to be ground. Also, remember to remove the weapon from the action palette before attempting to grind it. If you do not do so, you will not be able to grind the weapon.

With the release of Update 25, the GUARDIANS Colony has opened a special facility called the GUARDIANS Upgrade & Repair Station, and has located specialists from each manufacturer on the colony to allow the grinding and repair of weapons from all three major manufacturers, along with Kubara equipment, all in the same room.

This facility can be accessed from the regular elevators on the GUARDIANS Colony, and for more information on the weapon repair system, please see GUARDIANS Upgrade & Repair Station.

Grinding and Breaking weapons

When grinding a weapon, there's a chance of failure. If the weapon grind is succesful, the grind level goes up by one; for instance, from 3/10 -> 4/10. If the grind fails, the grind level goes down by one or two, and the maximum grind potential goes down by one - for instance, from 3/10 -> 2/9. When a weapon has reached six or more grinds, each break causes it to lose two grinds and one maximum potential - for instance, from 7/10 -> 5/9. Weapons can be repaired in the GUARDIANS Upgrade & Repair Station. Weapons cannot lose maximum grind potential below 4.

There is a 5% chance for C and B rank weapons to complete 2 grinds at once, and a 4% chance for A and S rank weapons to complete 2 grinds at once - e.g. from 3/10 to 5/10.

Grinding Success Rates

The odds for the grinding process to succeed are dependent on the following factors:

• The level of the weapon's current grind (0 to 9)
• The quality of the grinder (+1 to +10)

Shorthand	In-game Message	Actual Chance
Guaranteed	There is no chance of failure.	100%
Very High	The probability of success seems very high.	80% ~ 99%
High	The probability of success seems high.	60% ~ 79%
Fifty-Fifty	The probability of success seems to be about fifty-fifty.	40% ~ 59%
Low	The probability of success seems low.	20% ~ 39%

During periods where a grind boost is active, the numbers in the tables below will be increased by the amount specified. So for instance, during a 10% grind boost, the chance of successfully grinding a weapon from 9-10 using a Grinder S+10 goes from its usual 47% to 57%. The tables below are not manually updated during a grind boost. For information on what boosts are currently active, please see the infobox on the right-hand side of the wiki's front page.

Success Rate Tables

Grinding success is determined by the following factors:

• Grinder quality
• Weapon rarity
• How many grinds the weapon already has

The below tables show the success rates for the lowest-rarity weapons in each rank - 1★ for C, 4★ for B, 7★ for A and 10★ for S. As weapons increase in rarity (their number of stars) they become harder to grind. The method for working out grind difficulty is as follows:

Take the base rate as shown below for the rank of weapon you are grinding. Then, for each star above the rank's base rarity, subtract 2% from the grind success rate. Then, add 1% to the grind success rate for each point of quality in the grinder being used.

As an example, let's say you're grinding a 15★ weapon which already has five grinds on it. First, look up the base S-rank grind success rate for this grind - 83%. Since this is a 15★ weapon, 2% per star is subtracted, taking the success rate down to 73%. Then, we're going to use an S+5 grinder to perform this grind, which would take the success rate up to 78%.

At some point in the future, a separate page will be available with grind success rates for each rarity of weapon, but for now, please remember that the highest rarity weapons will be a touch harder to grind.

C-Rank Weapons

Grind
	0 → 1	1 → 2	2 → 3	3 → 4	4 → 5	5 → 6	6 → 7	7 → 8	8 → 9	9 → 10
1★ Base rate	100%	100%	100%	100%	96%	94%	92%	90%	86%	84%

B-Rank Weapons

Grind
	0 → 1	1 → 2	2 → 3	3 → 4	4 → 5	5 → 6	6 → 7	7 → 8	8 → 9	9 → 10
4★ Base rate	100%	100%	100%	100%	94%	92%	90%	86%	82%	80%

A-Rank Weapons

Grind
	0 → 1	1 → 2	2 → 3	3 → 4	4 → 5	5 → 6	6 → 7	7 → 8	8 → 9	9 → 10
7★ Base rate	100%	100%	97%	92%	87%	83%	79%	76%	65%	60%

S-Rank Weapons

Grind
	0 → 1	1 → 2	2 → 3	3 → 4	4 → 5	5 → 6	6 → 7	7 → 8	8 → 9	9 → 10
10★ Base rate	100%	100%	97%	92%	87%	83%	79%	76%	65%	60%

Grinding Misery Bonuses

If you've been unfortunate enough to break your weapon during grinding, not only can it be repaired at GUARDIANS Upgrade & Repair Station, grinding becomes a touch easier for each break the weapon is carrying. The values above are for weapons at X/10, and the following boosts can be applied when the weapon's maximum grind potential has been reduced:

Max grind	Grind bonus
X/9	+4%
X/8	+6%
X/7	+8%
X/6	+10%
X/5	+12%
X/4	+14%