Laying out your inventory
Your character's layout is usually a lot more restricted as compared to that of a storefront. However, the character's layout needs to follow the same design pattern you are using in your game.
These systems usually fall into a couple of patterns.
Rule of 99'
Players are limited to a certain number of each item. The number can vary based on the item (for instance, you can have only one weapon) or its effect on the player's load. As a rule of thumb, 99 should be the maximum number. However, it's up to you how your game will use the item to denote its maximum number.
In the Final Fantasy series of games, Rule of 99' was used throughout its inventory system, allowing the player to carry no more than 99 potions at a time, or anything else for that matter, as shown in the following screenshot:
Encumbrance systems
A system based on the strength, endurance, and energy of a player is a faux-style system. It ensures that the player cannot carry more than he/she is able to; generally...