In the console versions of the Skylanders games, the small colorful globes left behind by enemies or when winning an arena match are called Victory Points. When enough points are collected, the Skylander will gain a level up. In Skylanders: Spyro's Adventure, Skylanders can use Victory Points to get to the game's highest level: 10. In Skylanders: Giants, Skylanders can use the points to go to the highest level in that game: 15. In Swap Force, Trap Team, and SuperChargers, 20 is the maximum level cap.
Larger enemies and bosses will yield a much greater amount of Victory Points, and when you defeat an enemy with a Skylander that shares an Element with the current elemental zone, the amount of Victory Points yielded from the enemy is dramatically increased. Furthermore, as of Swap Force, all Victory Points collected in two player co-op are given to both players equally.
When a Skylander increases its level to a value that is greater than a level cap of an earlier game, and the same Skylander is used in an earlier game, the Skylander's level will be that game's level cap instead of the higher level. For example, if you leveled up a Skylander in Trap Team up to level 20, and you used that same Skylander in Giants, the Skylander's level in that game would be read as 15.
In the 3DS version of the series, the Skylanders upgrade by leveling up.