Ranking in Ninja.io can be split into 2 categories: skill levels and experience levels.
Skill Levels[]
Skill is calculated using a variation of the glicko2 skill rating system.
Skill can only be gained (or lost) in 1v1 matches.
When an account is created, it starts off with a default of 1000 skill points. If your account 1v1'd at any point before the update, your base points would be 1500, and the only way to reach 1000 again is to consistently lose matches. If you do not play any 1v1s for longer than two weeks, your skill value will slowly deteriorate down to 1500, if applicable. This can bring you to 1500 on the dot or drop you below to sometimes ~1480.
Depending on the amount of skill points your opponent has, if you draw in a game you may gain or lose points.
Winning against someone with a much higher skill rating will yield a lot of skill points, while winning against someone with a much lower skill rating will yield little to no skill points, and vise versa when you lose. If you leave a match while not clicking ready, you will lose a good amount of points, while the other player will get nothing but if you leave while in the match, the other player gains points and you still lose points.
Usually after creating an account, the first few games will either give you many more points or take away many more points, depending on if you win or lose. After this, the reward gets smaller while the points lost for losing increases in number to the point where your first few games give you 100-500 points per match because of the bonus after creating an account to 6-10 points per match and 25 points lost after playing for a while to 2-5 points per match and 60 points lost after you play a long time and have gotten a good rank. (This is also why the leaderboard is flooded with alts.)
The following skill titles can be obtained:
| Min | Max | Title | Icon |
|---|---|---|---|
| 0 | 799 | Newbie |  |
| 800 | 899 | Rookie |  |
| 900 | 999 | Beginner |  |
| 1000 | 1099 | Initiated |  |
| 1100 | 1199 | Competent |  |
| 1200 | 1299 | Adept |  |
| 1300 | 1399 | Skilled |  |
| 1400 | 1499 | Proficient |  |
| 1500 | 1599 | Advanced |  |
| 1600 | 1699 | Expert |  |
| 1700 | 1799 | Elite |  |
| 1800 | 1899 | Champion |  |
| 1900 | 1999 | Master |  |
| 2000 | 2099 | Grandmaster |  |
| 2100 | ∞ | Ninja |  |
Experience Levels[]
Players level according to a point system.
Private games do not affect the amount of experience gained.
A typical kill on an active enemy with K/D ratio higher than 1 will give between 100 and 200 experience points, but could be as high as 300 if it's part of a combo. If the enemy has K/D ratio of less than 1, then the amount of experience points rewarded will typically be between 0 and 100, unless a combo is involved. Killing sprees (double kills, triple kills, etc) will result in bonus points. Also getting "first blood" awards bonus points as well.
The maximum attainable level is be 240. It requires on average 260,000 kills of equally performing players to reach the highest level.
Every 16 levels, you get a new shuriken (note that these are not the same shurikens that you use to fight ingame):
experience level = 0.2 * √(yourExperiencePoints / 15.625)
| Min | Max | Shuriken |
|---|---|---|
| 0 | 15 | 
|
| 16 | 31 | 
|
| 32 | 47 | 
|
| 48 | 63 | 
|
| 64 | 79 | 
|
| 80 | 95 | 
|
| 96 | 111 | 
|
| 112 | 127 | 
|
| 128 | 143 | 
|
| 144 | 159 | 
|
| 160 | 175 | 
|
| 176 | 191 | 
|
| 192 | 207 | 
|
| 208 | 223 | 
|
| 224 | 239 | 
|
| 240 | ∞ | 
|