Let’s imagine a hypothetical game. A fantasy computer roleplaying game. Our hero is a great warriormage, who has been thrust into a political conspiracy. The themes of the game are choosing your sides in a world of grey morals. Along the way, our hero must battle ever-increasing monsters with sword combos, potions and simple magical spells. He is a capable alchemist and can make many kinds of potions and bombs from both conventional and rare essences found in the game. Now we need an inventory system, and by extension a whole system for collectible stuff. We also would like to put emphasis on realism, and since we have a ton of artists, let’s challenge them too.
First, let’s examine our hero. He is plagued by the difficulty of choice, the mystery of who to trust and whether he will survive the next battle. He helps peasants and solves problems, going by with the meager reward money for his troubles. He moves around a lot, often alone. This analysis would suggest that our hero is focused. He does not wait around. If he does not have a lead on the grand conspiracy, he helps those he can.
First, the most important variable object: The weapon. Our hero begins the game with a high-quality sword, forged for him by great dwarven smith. He also has another, heavier sword for different kinds of enemies, also of exceptional quality. Therefore, nearly every sword wielded by his enemies is inferior, and thus beneath our hero’s notice. The player can only carry two swords: One light and one heavy, and exchanging them is an important moment in the game that symbolizes choice and improvement. And what do you know: A human could reasonably carry two swords at any time, so we can animate our entire weapon inventory on our character model! Yay!
Now, armour. Same thing. It defines our hero, so the exchange of our armour should be a grand moment. At the beginning of the game the player can choose one of three different armour ”schemes” to compliment how he views the Hero. Like a blue tabard for a more royal take or a brown leather with belts for a utilitarian look. It won’t change the stats, though.
Then, money. Roleplaying game inflation is a really big problem. It ruins the game economy and implies the question: Where does he keep the twenty thousand gold coins? We are going to manage this by regulating the money we give the player. As our hero would undoubtedly not steal from peasants, we won’t put random barrels with 2-6 gold coins on the bottom in the game. Actually, we won’t put the option to loot dead people in either. Our hero is (usually) too busy saving the kingdoms to stop and go through the pockets of every damn guard he encounters. The only money we are going to give the player is the rewards from our quests. Now we know how much the player is going to make in the game.
What about other items? Now we must figure out what the hero would reasonably carry with him. A flint, some parchment, pen… Little items with which he keeps journal like some sort of obsessive diary addict. Spending time in the great outdoors is hungry work. Therefore food would be an important thing in his pack. Game mechanically food enables the player to use Rest. It heals HP, enables alchemy and advances in-game time. Since that is it’s only function, food could be simply represented in how many times you can camp. 2 or 3 would be a believable maximum.
Alchemy. Making items is fun. It brings out humanity’s primal aspect: Using a stone and a stick to survive in the grand wild. Therefore, we want to emphasize alchemy. Different potions and bombs require two things: Recipies and ingredients. Recipices are bought from witches and such with money. Ingredients are found in the nature and from fallen monsters. To avoid drowning the player in different ingredients, let’s just divide them in four categories: Common, Uncommon, Rare and Mythic ingredients. Most utility potions and bombs just require common and uncommon ingredients, which are found from common and uncommon plants and monsters. Powerful potions also require Rare ingredients, which are found from ”liutenant”-type enemies, which respawn in monster lairs. Mythic ingredients are used in permanent property-boosting potions, and are found from boss monsters.
There. Now we have 3 ”days” of food, a large pack of potion ingredients and alcemical equipment, several bottles of potions and a pouch of money. Try as I might, I cannot imagine carrying all of them comfortably in a swordfight. All this hard design work, and still not a reasonable inventory… right?
Actually, no. These items fit in a backpack or a large shoulder bag. And while I agree that they would get you killed in a mélee, there is no reason not to simply drop them. Let’s give the hero a reinforced shoulder bag. That is his entire inventory, minus five potions and five bombs. When the player draws a sword, he drops the bag in the same animation. And when the battle is over, the player just picks it back up. While the player is in no possession of the bag, he cannot access the inventory or journal. Whenever there is a larger battle incoming, we merely communicate that to the player so he can prepare his potions and yank the bag away at some point before the player goes past the point of no return. It’s also a nice use for major NPC:s. (Here, hold my bag. And don’t lose it!)
Without the bag, the player just has his swords and five potions and bombs on his belt. These can be accessed with hotkeys or a radial menu. If we deem necessary, he also has a maximum of 100 gold/florins/sovereigns. The potions created via alchemy are either consumed immiately or added to the belt. Same with bombs. And these ten items can also be reasonably modelled in the character model.
So there. A fantasy inventory system that makes sense with a fairly realistic character. For a completely hypothetical game, of course.