Item-based game saves are a concept in which a game requires the player to keep a stock of special items that must be spent in order to save game progress. If the player does not have the required item in stock, then progress cannot be saved. The purpose of this conceit is generally to build tension in the player. By limiting the number of times that the game can be saved, the player must weigh the risks between saving often and possibly not having a save item when one is needed, or remaining conservative and attempting to last as long as possible before giving in to the urge to save the game.
The most well-known example of this concept is found in the early games in the Resident Evil franchise. Saving the game in these titles is depicted through the use of a typewriter. However, in order to save the game, the player must have an ink ribbon; an item found in specific locations and in limited quantities only. Such ribbons carry a limited number of uses before becoming depleted.
This was meant to add to the tension of the Survival Horror experience; players had to choose between saving frequently and being safe, risking running out of ribbons, or saving infrequently and putting themselves at risk of losing more progress if they died. Most of the games provided an out for this on the Easy difficulty level; ink ribbons carried unlimited ink, meaning players could save at will without penalty.
Ultimately, this feature was removed when Resident Evil 4 was made. Although the player saved the game at typewriters as before, no item was required to save, and saves were unlimited on all difficulties. Resident Evil 5 did away with even the typewriters; the game is divided into strict levels, and can only be saved in between levels.