game design – Any ways to limit players other than a currency system or a resource system?

I’m making a 2D strategy game. I want to create something unlike the current resource management type games I regularly see tagged as strategy. In effect, I want some way to limit the player and force them to make hard decisions without introducing a currency or resource/crafting system.

I can see several benefits:

  • It’s not common
  • It leads to less repetitive gameplay
  • It allows for more varied styles of play
  • It forces the player to think and makes grinding impossible

However, I’m actually having a little trouble implementing this sort of idea alongside the idea of progression.

My original idea was to introduce a cap on how many of each type of item a player could have at any one time. In effect, this introduces some elements of an open-ended puzzle game. However, this limits progression:

  • If the number of items the player can have increases over time, this means that each individual item’s significance decreases over time. This has the effect of making decisions easier over the course of the game. Not what I want.
  • If the items get more powerful over time, then items acquired near the start of the game have no viability later on. I would like items to be at least partially viable at any stage of the game, to increase variety and make the game less linear. It turns the game into replacing old with new.
  • Simply increasing the variety of items over the course of the game is a sure-fire way to lose players early if they believe they are not making progress.

My implementation is workable, but simply not good enough for my personal standards and goals.

Is there a better way to let limits, choice and progression go hand in hand?

I use the word “item” here not just to refer to items in game, but other things such as spells, moves, buildings etc. that a player could acquire and use in the game.