More and more games ask for a phone number before letting you into ranked or competitive play. It can feel intrusive — so it is worth understanding what problem it actually solves.
Email is cheap; phone numbers are not
Anyone can create a new email address in seconds, for free, endlessly. That makes email almost worthless as a way to limit how many accounts one person controls. Phone numbers are different: they cost money, there are practical limits on how many a person holds, and getting a fresh one takes real effort. Requiring a phone number raises the cost of making throwaway accounts.
What it is used for
Phone verification serves several goals at once. It curbs smurfing — established players making low-ranked alternate accounts — by making each alt cost a phone number. It slows ban evasion: a banned player needs not just a new email but a new number. And it adds a layer of account security, since the number can be used to recover or protect the account.
How it relates to bans
Phone verification is not itself a ban system, but it works alongside one. A hardware ban makes a banned player's machine the obstacle; phone verification makes a fresh phone number another obstacle. Together they raise the total cost of coming back after a ban — which is the entire point.
The privacy trade-off
The cost is real: handing a phone number to a game publisher is personal data, and players are right to weigh that. The honest framing is a trade-off — stronger protection against smurfs and ban evaders, in exchange for sharing a number with the publisher.
The takeaway
Games ask for a phone number because email is too cheap to limit anything. It curbs smurfing, slows ban evasion and adds account security — a deliberate trade of some privacy for a fairer, harder-to-abuse system.