Tracing the Tendrils of Item Management

One of the things I learned while working on Dead Secret (big announcements coming soon!) is how complicated item combinations can be.  Combining items is a pretty standard Adventure game mechanic.  You allow the player to collect parts of an item from different locations, then combine those items into a new item that is necessary to progress.  Combine the herbs to make more powerful health items, combine the batteries with the flashlight to make it work again, combine the secret decoder ring with the mysterious page to read it.  If you’ve ever played any Adventure game you’ve probably combined some items at some point.

Horror games have used item combinations as a core puzzle mechanic since the very beginning, and it’s easy to see why.  Adventure games abiding by the puzzle dependency chart model allow the player to work on multiple problems simultaneously, but often need a synchronization point to gate progress.  Keys and locks get boring pretty fast, and item combination gives designers a way to make these synchronization points more interesting.

Item management in Resident Evil 2.

This all sounds simple on paper, but of course the devil lurks in the details.  In early Resident Evil games, item combination became part of your inventory management strategy.  In those games your inventory space is quite limited, so often you needed to combine items (shells, herbs, etc) just to free up inventory slots.  Inevitably there came a moment where you desperately needed to collect some item but didn’t have enough space for it, and item combination became an organizational tool.  Inventory management is a wonderful sub-game in the Resident Evil series, but from a production perspective it’s expensive to build.  You need UI to select items and combine them, some logic in the items themselves to determine when items and and cannot be combined, and maybe even some smart way to explain why certain item combinations are not good.  Resident Evil eventually implemented a number of changes to mitigate some of these complications.  For example, later games allow you to use a health herb without actually collecting it to get around the problem of death via full inventory.  Resident Evil 4 has hands-down the best inventory management system ever, but it’s also the most complicated to build.

More importantly, allowing player-controlled item combination makes it harder to communicate puzzles to the player.  If you want the player to combine the blade with the whetstone to sharpen it, then combine the sharpened blade with the hilt, then use the completed knife on the rope, you need to invent a reason that the blade can’t be used on the rope without the hilt.  You need to tell the player that the blade is too dull when he tries to use it on the rope without sharpening.  You need to invent a reason that the sharpened, completed knife can’t be used to cut other ropes, or as a weapon to stab the bad guy.  You must consider the possibility that your player doesn’t know what a whetstone is.  The more expressive your item manipulations become, the more the player will attempt complicated interactions.  It’s on the designer to come up with ways to respond to those attempts to avoid player frustration.

For Dead Secret, my goal was to keep item interactions as simple as possible.  In early design iterations items could only be collected or applied.  This kept the interface and communication requirements pretty reasonable.  But as we built out the game this simplistic item model became restrictive, so we changed it to allow for automatic item combinations.  When you collect all the necessary pieces of an object, the inventory system automatically does the combination work for you.  This approach has some pluses and minuses.  On the plus side, it keeps the UI simple but still allows for multi-step puzzles involving items that can be collected in any order.  This is particularly valuable in VR, where traditional user interface modes (e.g. the “pause screen”) don’t translate very well.  On the minus side, it removes the sub-puzzle of figuring out which item combinations make sense.  More importantly, it removes a degree of puzzle dependency control.  If parts for an item can be collected at multiple places, the item can be put together at any of those locations, and that has ramifications for progression.  There’s one spot in particular in Dead Secret where we had to do a bunch of work to accommodate this complexity in the dependency graph.

Inventory management in Dead Secret

Overall I’m pretty happy with the system we ended up with in Dead Secret, but it isn’t nearly as simple as I had initially planned.  Items can be collected, automatically combined, used as one step of a multi-step puzzle, and even automatically used up.  There are items that can be applied in multiple areas, items that can be used independently, and items that are entirely optional to collect.  There are secret items that have no icon and no presence in the inventory screen.  A seemingly simple design has turned out to have all sorts of tendrils, extending deep into the mechanics of the core game.  Even so, the item system in Dead Secret is much simpler than many other Adventure games out there.

Once you dig into the details, items and inventory system design is fascinating.  Seemingly minor changes to item usage rules can change the way a game feels dramatically.  Item collection, inventory space management, item upgrading and crafting, single-use items, items-as-weapons, disposable items, items that degrade, item boxes, item merchants–the derivations go on and on.  It’s probably a topic worthy of a lengthier post.

In leu of that, I’ll pose a question instead.  Take your favorite Adventure game, horror or otherwise, and consider the item system.  If you removed it entirely from the game, how much game would be left?

9 thoughts on “Tracing the Tendrils of Item Management

  1. A game without item management would turn out to be as old-fashion arcade style as it gets and just focus on Action or Strategy (e,g, Chess), so maybe it could be considered unidimensional.

    I expect Dead Secret to have a New Game +, Multi-Endings or even a mechanic like the one on Shadow Of Destiny (Memories) in which you get believable outcomes no matter how you play but you need to get each one so that the True or Complete one can be achieved.

    Which are the traditional platforms that Dead Secret will be playable? I have a PC with a Multi-touch Monitor (Dell S2340T), will I be able to experience the game with that technology?

    Keep it up and Best of Lucks with this Horror Game that you, a great person in the field is preparing for us. 🙂


    • Dead Secret has some of the things you mentioned, but I’m not saying which ones!

      You will be able to play Dead Secret on your PC sometime soon.

      • Chris, just saw the trailer for Dead Secret, and I’m very much looking forward to playing it. I’ve been a reader of this blog for years, and as I’m on my own “survival horror quest”, playing as many of these games that keep trying to scare me, I enjoy what you do so very much.

        I am very interested in what VR will do for gaming and Survival Horror in general, as the brain will not be able to process one “reality” for another in a well crafted VR experience, this will have extremely interesting psychological implications in the future. Nice to see that Dead Secret will have VR capacity in the future….a post on what you think about VR and Survival Horror would be much appreciated.

        Sorry this post isn’t about inventory UI, but as you hardly have time to publish here, I’m afraid you wouldn’t get a chance to be asked the question elsewhere.

  2. Well there are games like Myst and Amnesia which don’t have an inventory at all, but are all environmental + one on hand item puzzles.

    • True! We could consider those systems as incredibly limited space management (Myst only really has two things to collect if I remember correctly). Amnesia actually does have an inventory system (for oil, etc), it’s just not a main part of the gameplay. What is the effect of that approach? (I touched on one side-effect in my article on Ransacking).

  3. Hmm I don’t know how I personally feel about auto-combining inventory items as they are picked up.

    From a design perspective, I’m having a hard time seeing how doing this is any different from having 3 different colored keycards being required to open a door.

    Sure, thematically it’s definitely a more powerful tool since it’s no longer a literal key required to enter, but from a design perspective, is it really that different from your standard keycard door?

    • Well, from a design perspective, all of this is just keys and locks. That’s pretty much a direct quote from Ron Gilbert, the guy who developed and formalized the Puzzle Dependency Chart gameplay pattern that all of these games are based on. Keycards or multi-part statuette with missing gem eyes, the challenge format is the same: figuring out which objects can be used in combination. This is also the main mode of challenge outside of the inventory in most Adventure games: “applying” items to the environment to the progress is the main mode of play here, and it is, at its core, a key/lock model even if the lock is complicated and there are multiple keys.

      When we auto-apply or auto-combine objects, we’re definitely removing a little bit of thought from the mechanic. But there are other wins that might be more important as well. In particular, I’m thinking about avoiding frustration that stems from overly complex or confusing UI.

      Here’s an example. Once upon a time in every Adventure game ever, you would collect keys and then have to match those keys to specific locked doors. Resident Evil is an easy example: you get keys with crests engraved on them that are used on doors that have the same mark engraved on them. Once upon a time, these games required you to actually open your inventory, select the correct key, and apply it to the door. This is a straightforward item application mechanic, but in practice it can be super frustrating. If you haven’t figured out how to match keys to doors, every time you get a key you have to run around to all known locked doors and try them. Silent Hill 2 went out of its way to differentiate “broken” locks from “locked” locks so that the total size of the puzzle space didn’t become insanely huge. If there are a lot of doors, or if the distance between doors is far, this mechanic can be incredibly arduous. It’s significantly worse if you have more keys.

      To mitigate this, at some point (Resident Evil Code Veronica is the first game I can think of, but it might not be the first) games started just having a “key ring” where keys automatically go, and can be automatically used. Run up to the door, try to open it, and if you’ve got the right key then the unlocking is automatic. This significantly reduces the frustration of iterating over unclear key/door combinations, and allows these games to be less heavy-handed about the way key/door connections are associated. It removes a little bit of the thinking, but it does so in exchange for a large anti-frustration win.

      In Dead Secret we only have a few compound items, so automatic combination only happens every once in a while. Keys are automatically used in doors, though. You might lose a tiny bit of critical analysis gameplay by doing this (e.g. if I automatically put the batteries in the flashlight for you I’ve removed the need for you to think about putting the batteries in the flashlight yourself), but the anti-frustration and zero-overhead UI wins are a big deal.

      • Oh yeah I totally understand, I agree that there are significant wins to be had from reducing the UI complexity, specially for a VR title, so I’m not arguing that this isn’t right for your game.

        In terms of puzzles though, I’m keen on investigating for our own game multiple solutions to a puzzle. We have an ingame crafting system and one of the thoughts I’m having that would make it interesting is providing players with multiple ways to solve puzzles.

        As an example, let’s say you have a locked door. Typically, if this is a door we want the player to enter using a key, you’d put the key somewhere you want the player to go (across the level, near some enemies, etc). However, I’m keen on rewarding players who think outside the box if possible, so one of the solutions I’d like to have is allowing the players to craft explosives and blow the door away.

        Of course there’d have to be some sort of visual cue to let the player know they can blow this door up, like cracks, but I think there can be some creative ways you can take a traditional item combine mechanic and really make things more interesting in terms of puzzle solving.

        I know that I as a player, always felt bummed out when I thought of a solution to a problem that *should* solve it, yet because it wasn’t the “right way” I couldn’t use it.

        From a design standpoint I know it will create a lot of work, but I think it could be worth exploring.

        • I see where you are coming from, but item crafting is a fundamentally different design pattern than Puzzle Dependency Graph. I don’t think you can really mix them. Silent Hill 6 sort of tried and it was very bad, because you either lose the dynamic nature of crafting to fit your progression structure or you allow the player to screw themselves. Deus Ex and Dishonored have incredible dynamic world-based problem solving systems, and I think that’s similar to what you are talking about. But that design approach is a completely different thing than the Puzzle Dependency Chart pattern that’s being discussed here.

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