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
Mighty DOOM"You badly need to upgrade equipment to win against difficulty spikes."
Idle Cake Tycoon - Hamster Bakery Simulator"you need more and more of certain items"
GODDESS OF VICTORY: NIKKE"I feel like they are giving out more gems for free/ rolls since the start of the game and now"
Shadow Fight 3"not exactly because you can always upgrade the items which dont cost that much especially in middle/near end of the story mode and item power does not matter in events however in early game shadow energy is rare and items require upgrading after beating a boss and you have to get an item again after you beat a plane or you cant upgrade it"
RuneScape Mobile"Yeah, the in-game economy is a bit fucked."
Sky: Children of the Light"Seasonal items, even ones you spent money on, will most likely come back at some point. The only thing making them valueable is scarcity until they return, and until then are just used for bragging."
Cat Game - The Cats Collector!"Every single item from crafting to farming becomes more expensive/worth less. Waiting to spin for a chance to collect the cats takes exponentially longer, capping at 12 hours."
DRAGON BALL Z DOKKAN BATTLE"characters in the game are never completely useless its just that some of the stages are getting harder over time."
MARVEL SNAP"Cards can be nerfed by developers."
Disney Emoji Blitz"Early game items or items that you can obtain without paying are vastly less powerful than anything purchased or would require so much grinding that you’d have to make it a job."