Gacha is a game mechanic often seen in mobile and online games, where players spend in-game currency for a chance at a random reward - often characters or items. This guide focuses on how gacha mechanics work in Mahjong Soul, particularly the probabilities involved when pulling characters.

The base chance to pull a character is 5%. These 5% are split equally among all characters in the pool you're pulling from when there's no rate-up.

Currently there are 4 different versions of rate-up pools. But first, what does rate-up even mean? It means that one or multiple characters within the 5% have a higher chance of being pulled.

For example, Sakura Bloom, the pool for female characters, as of today (August 2025) has 41 characters. Without a rate-up event, every specific character has a chance of 0.12% (5% divided by 41) because they all share the base chance.
Now, let's say one of the characters gets a rate-up of 59% for a time. The percentage is applied to the base chance of 5%; so 59% of 5%. Instead of 0.12% the character has a 2.95% chance to be pulled, or roughly 25 times the chance. All the other characters in the pool share the remaining 2.05%.



This would be the first kind of rate-up, a single character in a 59% rate-up pool.
I'm only aware of two instances when this happens:

• a new character is introduced, and they get their initial rate-up
  
• the 'Fated Summon' event that happened in January this year (while I expect it will come again next January), in which you could select one permanent character of your choice to receive a 59% rate-up

The second kind of rate-up would be 59% while the rate-up pool is shared by 2 characters.

• This is the most common kind of rate-up for characters for which you can buy new or returning outfits. Since they share the pool, their individual base chance isn't 2.95% anymore but 1.475%.

The third kind of rate-up would be 59% while the rate-up pool is shared by 4 characters.

• This setup is typical for collaboration events, like Idolmaster or Fate. Although there have been collaborations with 3 characters, the standard of the last years has been 4. Since they share the pool, their individual base chance isn't 2.95% anymore but 0.7375%.

The fourth kind of rate-up would be 20%.

• Only once a year, exclusive characters make an appearance for a time. Li Yang is the one for 2025. The 20% rate-up is not used for anything else to my knowledge. The base chance to pull this character is 1%.

In the Summon area, on the left side, you can see all the available pools to choose from. When rate-up events are going on, the characters that receive the rate-up have their picture shown in the icon of the pool.



In the right corner, you see the "Details" Icon.



In the Summon area, this is the only place where they show the actual percentage of the rate-up. (You can also find this information in the "Info" section of the main screen or in the maintenance notes they currently exclusively post on x.)



The characters have a little "UP!" line in their frame, for rate-up, and in the beige banner, we can read about the shift in probability.
So, in this case, 2 characters share a 59% rate-up pool.



In this case, a single character is in a 20% rate-up pool.

1. 59% rate-up, 1 character (new character, Fated Summon)
2. 59% rate-up, 2 characters (permanent characters when outfits are sold)
3. 59% rate-up, 4 characters (collaborations)
4. 20% rate-up, 1 character (exclusive character)



This chart shows the statistical probability of getting at least one character from the corresponding pool when doing one or more pulls. 2.-3. considers aiming for a specific character within the rate-up pool (see Example 1).

A collaboration is going on with 4 characters. To get any kind of collab character, the base chance is 2.95%; you can check column 1. If you want a specific character, one out of four, you have to check column 3.

To get at least one character of the collaboration, no matter which, with 40 pulls, has a chance of 69.81%; aiming for a specific character from that collaboration, with the same number of pulls, would be a chance of 25.63%.

An exclusive character is offered (column 4.). 40 pulls have a chance of 33.10% to pull the exclusive character. What might be interesting for this kind of pool is the chance for the remaining characters to be pulled.


We can see that in any kind of rate-up event with 59% it's less likely to draw a character from the remaining pool. In the event of an exclusive character with a 20% rate-up, it's always more likely to pull a character from the remaining pool!

In this section, I want to bring the numbers that might be interesting when you want to get all 4 of the collaboration characters in an event.



The probability for the first character, while we don't care which one we get, is the standard 59% rate-up chart (1. in the last section). After we got the first, we don't want to draw it again. Which means the base chance is lowered by 0.07375% (2.95% divided by 4) to 2.22125%. After we got the second character, the base chance for the remaining two is 1.475%. To target the last single character column 3. of the rate-up chart from the last section is applied.


I changed the row for 40 pulls to 50 pulls for this chart (and 140 to 150), to bring the following example. You could plan to pull for 3 characters out of 4, and then buy the last one for 150 faith, since their chances are the lowest and even investing 100 pulls just for the last one, only brings a chance of 52.30%.

If we plan to use 50 pulls for the first, second and third character each, considering the lowered base chances at every step, we get 77.62%, 67.33% and 52.43%.

While the charts so far showed the chances for getting at least one character, the perspective on how many characters are likely with a higher number of pulls might be interesting as well.

Let's take the amount of Jade we get when we invests in the Fortune Charm for a year. 60 Jade every day + 300 Jade bonus every month = 25,500 Jade, which is 14.16 ten-pulls, or 140 pulls.

Quick Comparison - getting enough Jade for 14 ten-pulls

Fortune Charm

~$70 over 1 year

buying Jade directly

~$220 with First Purchase Bonus* ~$400 without bonus

*The First Purchase Bonus grants double the Jade on the first purchase of every different tier of Jade package once a year. It resets during the Mahjong Soul birthday event at the end of April.



Here are the statistical chances for the number of characters (No.) with 140 pulls.


So, with 140 pulls, there's a 70.58% chance to hit the base character pool at least 6 times.

Let's look at the 59% rate-up pool in terms of collaborations (that happen twice a year currently) and assume there are 4 new characters in each collab. We'd need to hit the pool at least 8 times to get the 8 characters (ignoring the possibility of drawing the same character more than once). With 140 pulls, the chance for that to happen is only 5.65%.
Maintaining the Fortune Charm for a year is not enough to have a good chance of getting all characters from both collaborations.

If we save all Jade for a year for the exclusive character (20% rate-up), we have a 75.51% chance to get them.

Generally, in conversation, the pools are rounded. Instead of 59%, people say 60%. I took the numbers from the game to be as precise as I could.

Q: If I buy 1800 Jade for a 10-pull, what are my statistical chances?
A: That depends on the pool you want to use your 10-pull for. Please check "How Do I Know Which Rate-Up Pool I'm Dealing With?" and then "Probability Charts For Multiple Pulls".

Q: When is the best opportunity to get a specific character?
A: Either during their introduction or the "Fated Summon" (January 2025) event, when they get the 59% rate-up without having to share the rate-up pool with any other character.

Q: Why aren't there more questions here?
A: Because I don't know what else might be interesting to you. I'll update this section based on the comments.


Bonus: Etymology
The word gacha comes from Japanese: ガチャポン, gachapon, describing the sound of pulling the lever of a capsule machine (gacha) and the sound of the capsule falling into the capsule retrieval slot (pon). A close English translation could be 'Kaching-Clonk'.