Items, Equipment and inventory

Hi everyone!

I'm designing the inventory system for my upcoming RPG but I'm not sure how I want it. There are several questions. The game is some form of party-based tactical hack 'n' slash style game. I'm not entirely sure if it'll use a modern/futuristic setting or a fantasy setting, but I'm leaning towards the modern one. Anyway, onto the questions.

1. Should the items in it have different sizes? In many games, items have varying sizes in slots. A potion might use a single slot while a sword might use 1x4 slots and an armor 2x3 or whatever. This makes the player unable to carry around too many large objects, even if they have low weight but doesn't really work with the idea below I think.. What alternatives do I have?
2. Should I present the item list as slots or as a scrollable list with more details? Most games I've played/looked at have an inventory which looks like a grid of icons. In some games, all items use one grid cell while other games have varous sized objects (usually rectangular though). This makes it easy to get a quick overview, but usually requires hovering the item to find out what it really is. I've thought about using a list-based inventory instead in which each item would get it's own row-group (or whatever) which would display an icon, the name/type and perhaps a description or stats. This list could potentially be filtered to only show items equipable on a specific body part for example.
3. Should the character always have his inventory or should it be dependent on equipment? In most if not all games I've played, the characters always have an inventory of some size. In some games, there are special items which act as containers (Horadric cube, belts in D2) or level/progress based (bags in Titan Quest), but the overall idea is that the items are carried by the character in some magical fashion. I'm considering using container-items instead. Characters can hold any item in his hand, and he can equip a backpack in which he can then place other items. Without a backback or bag, the chacter can only bring two items (one for each hand). This could allow the player to prepare a few different backpacks and pick the most suitable when he gets a quest/mission.
4. How should I present equipable items and body parts? Titan Quest has slots surrounding an image of the character and each slot has a background icon to explain which items you can place there. In Shadows Over Riva there's this dark humanoid character with slots surrounding it, but using arrows/lines to associate a body part with each slot. The main problem (?) I have with this is that you can only equip one item for each slot. What if I want a bullet proof vest under a shirt under a jacket? Give the character three slots? What about dropping the slot based equipment and using some form of list instead, where each equipped item could give penalties such as reduced agility? How would I present those lists? Bring it up when the user clicks the associated body part on some doll?
5. Quick-access slots? Let's say you have a grenade with you. You'd probably want to be able to throw it without opening up your inventory. In D2, you have the belt which allow you to quickly access potions. I want something similar, but for arbitrary items. If I went with idea #3, I could allow pretty much any item be a container. This got me thinking about tactical vests with 4-8 quick-access pockets which could hold a single small item each. Each usable item in a quick-access pocket would then get a clickable button in the interface. I'm afraid this could get messy though. What do you think? I think it could be very cool, but it would need a really good interface..

1. Sure. If you use the lists, you could make the items take up multiple list slots; or, create another stat called Space/Slots to which the item will take up. I would limit the number of list slots so that it won't be too overwhelming, so it could also be shown all at once for quicker access.

2. Don't make it scrollable as I think it is better for the player to have quicker access to inventory. Show everything at once, and if you can't do that, limit the number of slots available. Maybe 3-4 on the chest/main body at most.

3. If you make it dependent on equipment, your number of slots may increase as you gain more levels; you get better equipment and etc.

4. You could make multiple lists, each a body part, and organized under their respective body parts in the inventory screen. You could make it so that you won't have to click on a body part to access its list; the list simply shows everything.

1. Should the items in it have different sizes? In many games, items have varying sizes in slots. A potion might use a single slot while a sword might use 1x4 slots and an armor 2x3 or whatever. This makes the player unable to carry around too many large objects, even if they have low weight but doesn't really work with the idea below I think.. What alternatives do I have?
2. Should I present the item list as slots or as a scrollable list with more details? Most games I've played/looked at have an inventory which looks like a grid of icons. In some games, all items use one grid cell while other games have varous sized objects (usually rectangular though). This makes it easy to get a quick overview, but usually requires hovering the item to find out what it really is. I've thought about using a list-based inventory instead in which each item would get it's own row-group (or whatever) which would display an icon, the name/type and perhaps a description or stats. This list could potentially be filtered to only show items equipable on a specific body part for example.
3. Should the character always have his inventory or should it be dependent on equipment? In most if not all games I've played, the characters always have an inventory of some size. In some games, there are special items which act as containers (Horadric cube, belts in D2) or level/progress based (bags in Titan Quest), but the overall idea is that the items are carried by the character in some magical fashion. I'm considering using container-items instead. Characters can hold any item in his hand, and he can equip a backpack in which he can then place other items. Without a backback or bag, the chacter can only bring two items (one for each hand). This could allow the player to prepare a few different backpacks and pick the most suitable when he gets a quest/mission.
4. How should I present equipable items and body parts? Titan Quest has slots surrounding an image of the character and each slot has a background icon to explain which items you can place there. In Shadows Over Riva there's this dark humanoid character with slots surrounding it, but using arrows/lines to associate a body part with each slot. The main problem (?) I have with this is that you can only equip one item for each slot. What if I want a bullet proof vest under a shirt under a jacket? Give the character three slots? What about dropping the slot based equipment and using some form of list instead, where each equipped item could give penalties such as reduced agility? How would I present those lists? Bring it up when the user clicks the associated body part on some doll?
5. Quick-access slots? Let's say you have a grenade with you. You'd probably want to be able to throw it without opening up your inventory. In D2, you have the belt which allow you to quickly access potions. I want something similar, but for arbitrary items. If I went with idea #3, I could allow pretty much any item be a container. This got me thinking about tactical vests with 4-8 quick-access pockets which could hold a single small item each. Each usable item in a quick-access pocket would then get a clickable button in the interface. I'm afraid this could get messy though. What do you think? I think it could be very cool, but it would need a really good interface..

Here's my personal opinion:
1. I don't like the different size approach, I'm more of the simple one size fit them all approach. Instead of size you could use weight.

2. Lists as inventory is bad design. Use a tighly packed inventory screen with adequate icons and put all informations in a mouse-over window.

3. I'm really a fan of backpacks defining how many items you can carry around.

4. Many games support assembling/disassembling items(modifications). This way you could create a new item like a bullet proof vest on-the-fly and disassemble it later when you don't need it any longer. I would avoid stacking many items, I once played a RPG where you could wear several layers of clothes, even as core gamer I found it too much.

5. It depends on game design. If you want to deliver a short-cut only to access items faster than opening the inventory, select an item and execute some operation on it, then you only need an inventory independent gui window where you can drag'n'drop items for quick access. When you want to restrict the number of items available i.e. in combat, a tactical vests with some 4-8 pockets which could hold small items only, would be fine. The question is, is it a game feature or a gui feature ?

I would go more on weight as a hindrance to item collection rather than the amount and size of the backpacks you have purchased. There should certainly be a cap to the amount of things you can hold, but I didn't much like how WoW and newer generations have handled backpacks. UO had the best, for my experiences(and the type of game) and I also dealt with DAoC's rather well. There was a predetermined amount of space available, but the amount was not so few you couldn't venture for a while without hitting a vendor. Make items collected worth being collected rather than allowing "junk" loot.

1. Should the items in it have different sizes? Frankly, I would have to say no. I'm sure there are people (such as myself) who found certain games (Dungeon Siege, Neverwinter) with such restrictions interesting. When done properly, it can add a non-negligible amount of realism and fun. These systems tend to work well with games that place a higher importance on items and, as a consequence, there are fewer overall items to "pick up" from a given encounter. That said, I have to be honest and say that, on the whole, most size based inventory systems do nothing other than exacerbate the frustration of a full inventory. It becomes an issue when players get "in the groove" and are "pwning", or whatever you'd like to call "having fun out in your game world", they tend to ignore the auto-loot (or just mindlessly click) in favor of beating monsters and leveling up. Then their fun comes to a screeching halt when they discover that they still have inventory space, but they have to spend an inordinate amount of time playing inventory-tetris when they're in the middle of plowing through a dungeon. Also, in terms of simply implementing an inventory system, it's much easier to use a 1:1 ratio on a fixed size bag. Using a display-independent attribute of an item (such as weight) lets you add interesting mechanics without having to change your (general) inventory display code. If you are bent on using size as a factor, my only suggestion is to be very careful as to how you design your items. Squares and rectangles are easy to use and have the advantage of requiring a given object to logically occupy a certain space even if the model doesn't, eliminating a lot of annoying edge-cases where a user might try and "fit" various objects together to get more space but leaving you free to use any model you'd like.
2. Should I present the item list as slots or as a scrollable list with more details? As others have said, definitely "all in one" as much as you can. Most games that use lists tend to pre-sort the items into various logical "buckets" in advance and presented in an "all in one" façade for the user so the lists aren't overwhelming. Even though the items are presented as lists, the user has an intuitive grasp of where any given item should be spatially located both on and off the screen.
3. Should the character always have his inventory or should it be dependent on equipment? Depends on your game. My only advice is that if you use a progressive system for inventory management make sure the player knows what they can expect. A simple "you only have 2 items now but soon you can get a backpack!" goes a long way. There's a fine balance between making item selection interesting and using it as a cheap means to gimp the player. Your "backpack switching" concept sounds quite nice and will probably be well received by organized pack-rats.
4. How should I present equipable items and body parts? Depends on your game. Frankly, how many items a player can equip per body part is a game balance issue that you should resolve well in advance. As for the actual display, the easiest "visual" way to do it would be with a doll and various GUI elements. Lists, or simply having multiple visible "slots" to place items in. You could also do use a "layer" method depending on whether certain "layers" qualified as actually being used in combat vs. merely being eye-candy. As Ashaman73 said, try and favor enhancement composition over wholesale replacement. Instead of having four different armor layers, have an item that grants certain bonuses to the current armor with a neat new graphic (color change, texture switch, etc. ) instead.
5. Quick-access slots? Agreed with Ashaman73's answer. I would just add that, in my opinion, the base system should be more of a game-feature since technically you might wish to display those "quick slots" - as they're designed as a part of your inventory - in more than one way (quick action bar + character screen, as an example). Seems like a standard model-view-controller at first glance.

Thank you all for your replies!

I think I need to add some information about the game. I don't imagine it beeing much of a loot hunting game, but more of a "do missions to earn cash to buy stuff" game. There will be items you can pick up etc, but not so much for selling them as for using them yourself. I will do this by making the shops buy-prices low and mission reward prices high so that it's simply not very rewarding to sell stuff.

I think I'll go with backpacks for inventories and just let the characters start out with one each. There will be a weigth factor limiting how much you can carry before getting penalties, but I also want to limit by volume somehow. I don't really want an arbitrary X items limit, since I want to be able to carry 50 grenades without being able to carry 50 machine guns.. Inventory-tetris is bad, but the situation can be improved by some sort-button, or a fit-this-item button. Another solution would be to let each container display a volume bar or a percentage of how full it is.

Early in the game, if not already from the start, the player will recieve a personal HQ for his party. There he can store pretty much any amount of items, and it's where he gets most of his assignments (people come there to ask for help). I imagine the player returning there pretty often to resupply and to change equipment to better suit current mission.

As for the quickslots thing, it would be a game feature, that only items placed in quick-access bars are quickly accessible.

Thank you all for your replies!

I think I need to add some information about the game. I don't imagine it beeing much of a loot hunting game, but more of a "do missions to earn cash to buy stuff" game. There will be items you can pick up etc, but not so much for selling them as for using them yourself. I will do this by making the shops buy-prices low and mission reward prices high so that it's simply not very rewarding to sell stuff.

I think I'll go with backpacks for inventories and just let the characters start out with one each. There will be a weigth factor limiting how much you can carry before getting penalties, but I also want to limit by volume somehow. I don't really want an arbitrary X items limit, since I want to be able to carry 50 grenades without being able to carry 50 machine guns.. Inventory-tetris is bad, but the situation can be improved by some sort-button, or a fit-this-item button. Another solution would be to let each container display a volume bar or a percentage of how full it is.

Early in the game, if not already from the start, the player will recieve a personal HQ for his party. There he can store pretty much any amount of items, and it's where he gets most of his assignments (people come there to ask for help). I imagine the player returning there pretty often to resupply and to change equipment to better suit current mission.

As for the quickslots thing, it would be a game feature, that only items placed in quick-access bars are quickly accessible.

You could have "stacked" items to avoid the 50 of this small item vs 50 of this large item issue. You could have a container that specifically holds your grenades thus keeping them separate from your normal inventory. In Dark Age of Camelot archers had to keep many arrows on hand to fight with. Over time, player input, and common sense to a lesser degree, took hold and they added quivers. Only four slots, but that could hold at least 400 arrows, thus reducing the amount of inventory space they hogged putting them on par with other classes in the game. I believe WoW had quivers as well, but I believe they ate up a bag slot if I am not mistaken.

1. Not unless the item was important or theoretically large.
What I mean is, generally everything should be a similar size except like a horse or a very important multi-quest item.

2. The list looks easier, go with that.

3. Nope always inventory. Unless an important storyline, battle or unique quest is coming up always include an inventory.

4. My opinion, go with the slots. The player will have to choose the best armor or buy a better efficient one.

5. Yes, but no to the clickable. Make it a hot-key instead.