League-of-legends – What does the second number in the ranking table mean

All players should pick a random hero, and everyone should only go into the middle lane.

League of Legends' Free-to-Play model allows gamers, paying or not, to enjoy all of the core gaming experience.

So every element that actually makes a difference in the gameplay can be acquired for free (champions & runes). There are more than 60 champions in the game and they are locked for you when you create an account; you buy a champion for a given price with in-game money (IP - Influence Points) earned by playing the game, or you spend Riot Points. Runes give you a small boost in-game, and can only be bought with IP.

Riot Points (RP - acquired spending real money) are used for:

• Boosting Summoner Experience/IP gain per game (summoner level cap is 30)
• Buying champions
• Skins (cosmetics)
• Changing your Summoner Name (more cosmetic, basically)
• Others (Bundles, Extra Rune Pages, etc.)

In short, not spending money means you will take longer to unlock all features (which are not required for having fun with the game), you will not have skins, and your Summoner Name is fixed.