Gen VI Capture Mechanics

Thanks to magical for locating, analyzing and publishing the capture routine.

Capturing in the sixth-generation games is not much changed from the fifth generation, but brings back the four shake checks from the third- and fourth-generation games. If you'd rather read about the more different algorithms from the first two generations, see here or here. The catch rate calculator, which can calculate for you how likely you are to succeed in capturing a certain Pokémon, is here.

The Catch Rate Formula

The game starts by calculating the final capture rate, in a manner essentially identical to the fifth-generation games:

`X = (((3M - 2H) * G * C * B) / (3M)) * S * O`

The variables involved are basically the same as in the fifth generation or analogous to them: current and maximum HP (H and M), the grass modifier (G), the intrinsic catch rate of the species (C), the ball bonus (B), the status condition if any (S), and the O-Power bonus (O).

M (Max HP) and H (Current HP)

As usual, this is the maximum and current HP of the Pokémon being captured. When the Pokémon is at full health, X will equal just about G * C * B * S * O / 3, and lowering its HP will bring it to something close to G * C * B * S * O.

G (Grass Modifier)

I call this the grass modifier because it appears to be basically the exact same thing as the fifth-generation grass modifier, which would decrease the capture chance while in dark grass if you had too few Pokémon caught in your Pokédex. The sixth-generation games don't include dark grass in quite the same sense as the fifth-generation games, however, and technically we don't yet know the exact condition that activates this part of the formula - the game checks the battle type/terrain (the same thing it checks to see if we get a bonus from the Dive Ball), but we don't know exactly what the value it tests for represents. From in-game testing, it's not OR/AS hidden Pokémon battles, long grass, or darker grass. If you have any ideas on what it could be, let me know.

In any case, when we're not in the unknown terrain/battle type, the formula skips applying this modifier - you can treat it as if the G value is 1. When we are in that terrain/battle type, however, the value is modified depending on how many species are registered as caught in your National Pokédex, the same way as in the fifth generation:

Number of species caughtModifier
More than 6004096/4096 (1)
451-6003686/4096 (~0.9)
301-4503277/4096 (~0.8)
151-3002867/4096 (~0.7)
31-1502048/4096 (0.5)
0-301229/4096 (~0.3)

So, all in all, in the mystery terrain, it is extremely difficult to catch Pokémon at the beginning of the game, when you've caught few Pokémon, and it only becomes as easy as normal when you have more than 600 Pokémon caught.

C (Capture Rate)

This is the intrinsic capture rate of the Pokémon species you are attempting to capture, a number ranging from 3 (hard-to-catch legendaries) to 255 (common easy-to-catch mostly-early-game Pokémon). For X and Y, you can look this up in any decent online Pokédex, such as veekun.

Omega Ruby and Alpha Sapphire, however, complicate things slightly by altering some catch rates, and I've yet to find any online Pokédex with the updated catch rates. The basic idea is that legendaries who have been mandatory catches for the storyline in earlier games, and were therefore given a higher catch rate than normal, now have the regular legendary catch rate of 3: this includes Kyogre, Groudon, Dialga, Palkia, Reshiram and Zekrom. (Kyogre and Groudon are not mandatory storyline catches, since if you knock your version's primal legendary out in the Cave of Origin the first time around, you'll get a second chance after finishing the game.) Meanwhile, since Rayquaza is a mandatory storyline catch in OR/AS, Rayquaza's catch rate has been bumped up to 45 to help you along.

B (Ball Bonus)

Here's where the Pokéball you're using comes in. This is a multiplier, determined as follows:

Poké Ball, Premier Ball, Luxury Ball, Heal Ball, any ball not listed
B = 1
Great Ball
B = 1.5
Ultra Ball
B = 2
Master Ball
The formula is not used; the capture is always successful
Net Ball
B = 3 if one of the Pokémon's types is Water or Bug; B = 1 otherwise
Nest Ball
B = ((41 - Pokémon's level) / 10), minimum 1
Dive Ball
B = 3.5 when on or in water; B = 1 otherwise
Repeat Ball
B = 3 if the Pokémon's species is already registered as caught in the Pokédex; B = 1 otherwise
Timer Ball
B = 1 + (number of turns passed in battle * 1229/4096), maximum 4. Since 1229/4096 is approximately 0.3, the bonus reaches its cap on the eleventh turn.
Quick Ball
B = 5 on the first turn of a battle; B = 1 otherwise
Dusk Ball
B = 3.5 at night and inside caves (note that Mirage Caves in OR/AS do not count as caves); B = 1 otherwise

This is all exactly the same as in the fifth generation.

S (Status)

This is a modifier based on whether the Pokémon is afflicted with a status ailment. Like in the fifth generation, if the Pokémon is asleep or frozen, S = 2.5; if the Pokémon is poisoned, paralyzed or burned, S = 1.5; and otherwise, S = 1.

O (O-Power Bonus)

This value replaces the Entralink modifier of the fifth-generation games to factor in Entralink powers' sixth-generation analogue, O-Powers. However, while Entralink Capture Powers could only provide a 30% bonus at the most, the Capture O-Powers are considerably more effective: Capture Power Lv. 1 gives an O value of 1.5, Lv. 2 gives an O value of 2.0, and Lv. 3, S and MAX all give an O value of 2.5. If no Capture Power is active, the O value is 1.

Critical Captures

Critical captures are back from the fifth-generation games and work pretty much the same as they did then. Sometimes, when throwing a ball, it will make a whistling sound when thrown, shake once in mid-air, and then shake once on the ground before either breaking or successfully capturing the Pokémon. A critical capture is much more likely to succeed than a regular capture, as will be explained below. The chance that a given capture will be critical is calculated as follows:

`"CC" = |__(min(255, X) * P) / 6__|`

CC is then compared against a random number between 0 and 255 inclusive. If the random number is less than CC, the capture will be critical. Thus, the probability of a critical capture is CC / 256, and depends both on the already-calculated final capture rate X and on the Pokédex modifier (P).

P (Pokédex Modifier)

Much like the grass modifier in the formula for X, this value depends on how many species of Pokémon you have caught:

Number of species caughtModifier
More than 6002.5

In other words, critical captures become likelier as you capture more Pokémon, making it just a touch easier to catch those last few, but are downright impossible at the beginning of the game, when 30 or fewer Pokémon have been caught.

Throwing a Ball

So here's where we finally get to the part where something is a bit interestingly different from the fifth-generation games.

If you've played the sixth-generation games, you'll have noticed that Pokéballs can break after zero, one, two or three wobbles again, like in the older games but unlike the fifth generation where they never broke after two. The change in the fifth generation happened because the game, effectively, only gave the Pokémon three chances to break out of the ball instead of four (I will explain how this works in a moment). However, this was a somewhat awkward change, because previously each failed breakout attempt would be represented by one visible wobble on the screen, while in the fifth-generation games the second failed breakout attempt would randomly seem to correspond to two visible wobbles.

The sixth-generation games fix this awkwardness by giving the Pokémon four chances to break out again in non-critical captures, like in the third- and fourth-generation games. However, they also changed the way the breakout chance is calculated, so as to make the final success rate of a regular capture the same as in the fifth generation.

Specifically, if X is 255 or more, the capture will automatically succeed. However, otherwise a second number Y is calculated from X:

`Y = |__65536 / (255 / X)^(3/16)__|`

Note that the power of 3/16 you see there used to be a fourth root - a power of 1/4 - in the fifth-generation games. Here the value below the line is lower, meaning the Y value is higher.

Once Y has been determined, the Pokémon will make up to four attempts to break out of the ball, except in a critical capture, where it will only make one. For each attempt, a random number between 0 and 65535 inclusive is generated; if this random number is greater than or equal to Y, the Pokémon will break free. If every attempt fails, the Pokémon is successfully caught; otherwise, in a regular capture the number of times the ball wobbles is equal to the number of failed tries the Pokémon made before it broke out, whereas in a critical capture you will always see the ball wobble once before it breaks.

The probability of a single random number being less than Y (that is, the probability that the breakout attempt will fail) is Y / 65536. Thus, the probability that all four attempts in a regular capture will fail is (Y / 65536)4. Plugging the Y formula into that tells us the regular capture chance is (X / 255)0.75, exactly the same as the fifth-generation chance. However, a critical capture succeeds if just one random number is less than Y, the chance of which is now equal to (X / 255)0.1875, rather than (X / 255)0.25 as in the fifth generation - in other words, while regular captures are equally likely to be successful as before, critical captures are now even more significantly more likely to succeed than regular captures.

The total probability of a successful capture equals the chance of a successful critical capture plus the chance of a successful normal capture: namely, (CC / 256) * (Y / 65536) + (1 - CC / 256) * (Y / 65536)4. There is no less cumbersome way to write that equation, I'm afraid; if you want to calculate your chances, you're better off using the calculator.

Catch Rate Calculator

Oh, yeah, there's a calculator. The sixth-generation catch rate calculator will do all the math for you and tell you how likely you are to capture the Pokémon without you having to do any of these calculations yourself.

Page last modified November 10 2016 at 00:23 GMT