Power Creep
A permanently purchased item in the game becomes less valuable over time.
Power creep is a term used to describe a situation where an item in a game depreciates in value over time. The main way this happens is via new content being added to the game that make the old content less valuable.
The idea is that you may have earned or paid for a powerful item or upgrade in the game. It may have been great for awhile, but new better items are available or the power level of the opponents has increased to the point where that original item is no longer useful. The money and time that you previously spent to earn that item is now worthless and you must spend more money and time on the new more powerful item to have the same benefit that you had before.
If games do this often, it encourages players to keep spending money to stay competitive. If done incorrectly by the game developer, it also has the effect of making the game boring for new players who start with the new powerful items which are overpowered against the opponents found in the beginning of the game. The original game can become unbalanced if too many updates are made that keep adding more and more powerful items.
The idea is that you may have earned or paid for a powerful item or upgrade in the game. It may have been great for awhile, but new better items are available or the power level of the opponents has increased to the point where that original item is no longer useful. The money and time that you previously spent to earn that item is now worthless and you must spend more money and time on the new more powerful item to have the same benefit that you had before.
If games do this often, it encourages players to keep spending money to stay competitive. If done incorrectly by the game developer, it also has the effect of making the game boring for new players who start with the new powerful items which are overpowered against the opponents found in the beginning of the game. The original game can become unbalanced if too many updates are made that keep adding more and more powerful items.
Examples
Drilla: Idle Gold Miner Game"There are "permanent upgrades" that eventually lose its value, and you feel you want to buy another one. They are bought with... Crystals of course."
Invasion: Modern Empire"game is constantly increasing in power levels, 9 years ago the maximum was 4 star troops and HQ21, now it is 6 star troops and glory 6 HQ (HQ 25 + 6, so 31)"
Space Arena: Build & Fight MMO"ships with more cells release over time"
Legends of Runeterra"New cards are better than older ones"
Asphalt 9: Legends"Cars generally keep their use and are often tied to exclusive benefits that can always appear again. However, the game makes an agressive push for chasing newer content, and the competitive side of items is at constant risk of being overshadowed."
Top Eleven Be a soccer manager"Promotions diminish the quality of players."
Ping Pong Fury"There's a straightforward progression system that gradually renders all items obsolete, but only if they're not the best of the best."
Yu-Gi-Oh! Duel Links"I hate the meta"
War Robots Multiplayer Battles"Every update no matter how minor"
SimCity BuildIt"over time new materials and battle items get introduced and old ones become very slightly faster"