Penguin Level, or simply level, is a measurement of progress used in Club Penguin Island. All players start at level 0 and can increase their level by gaining rank, which is received in the form of XP (short for experience) from quests. The player's level is the sum of their rank for each quest-giving character. For instance, if a player's Aunt Arctic (green) rank is 2 and their Rockhopper (red) rank is 3, the penguin's level is 5.
Currently, the highest possible level is 18. Prior to the 1.3.0 update, it was 15, and prior to 1.2.0, it was 12.
In order to increase rank, players must complete either Daily Challenges or adventures, which yield XP. After a player receives a certain amount of XP, they raise in rank. After they raise in rank, they also raise in level.
The character the daily challenge is associated with or adventure is given by determines which color of XP the player receives. For instance, completing the adventure "Leaky Landing", given by Aunt Arctic, yields green XP, as does the Daily Challenge "Good Altitude", which is labeled with Aunt Arctic's face. Daily Challenges always yield 20 XP each, while the amount from adventures varies. Additionally, adventures only yield XP the first time they are played, and replaying will not yield XP again.
Aunt Arctic XP is received by completing quests and adventures from Aunt Arctic. Rockhopper XP is received by completing quests and adventures from Rockhopper. Currently, the highest possible rank for each is 9. Prior to the 1.2.0 update, the highest for Aunt Arctic was 6, and prior to 1.3.0, the highest for Rockhopper was 6 as well.
As of the 1.0.1 update, unlocked adventures are now shown along with rewards, although they are still unlocked by increase in rank, and are independent of levels.
XP gain is mostly exponential, and as such, higher ranks require greater or equal amounts of XP than previous ranks. Effectively, 7880 XP total is required to reach the current maximum level of 18.
XP required from previous rank
Adventure XP requirements and rewards
Adventures require the player has a certain rank or higher in order to play.
The Sharing Pack (level 5) and Town Heroes Pack (level 15) have the most rewards of all packs, with each having the maximum seven rewards. The Fame Pack (level 3) has the least, at only two rewards, and is also the only one without decals.
Since the 1.0.1 update, the "available in shops" rewards now show the cost of Party Supplies, overlayed in the corner of the supplies' icons.