Ways to increase Item Find:
How does the game decide to award you items, and how does the item find stat affect that?
There are two very broad groupings of items: Enemy Items, and Area Items. Enemy Items are almost always resources (bone, teeth, blood, etc) and Area Items are almost always equipment (swords, shields, armor, etc)
There are a handful of exceptions to this: Wood, a resource for example, is both. It can be dropped by the Iron Chef enemy specifically, but also anywhere in the castle as an “Area Drop.” Sulfur on the other hand, another resource, is only an Area Drop and never comes from an enemy.
Enemy Drops can only be triggered by defeating enemies. Area Drops can be triggered by defeating enemies OR opening chests. Chests can only give gold or Area Drops, never an Enemy Drop. (unless the Enemy Drop in question is ALSO an Area Drop, like wood)
Every enemy in the game has its own drop rate. The vast majority have a 1 in 9 chance to drop something. A handful have higher and lower ones, but it’s not really important for this discussion. This is where the item find stat will first come into play: every ten points of item find will increase your initial enemy drop chance by one. So if you have 10 item find and the enemy has a 1/9 drop chance, it becomes 1/8. If you have 80 or more item find it becomes 1/1, a guaranteed drop.
Now let’s say the enemy has decided to drop something. What do you get? The enemy has a 67% chance to give you an “Enemy Drop” and a 33% chance to give you an “Area Drop.” Item find will never affect this. The vast majority of enemies have exactly one “Enemy Drop” associated with them, and like I said earlier, it’s almost always a resource. Some enemies have no Enemy Drop, some have two. At any rate, if the 67% chance triggers, you will be given a random Enemy Drop that is held by that enemy. If the 33% Area Drop chance triggers, OR the enemy doesn’t have an Enemy Drop, you will get the Area Drop.
Side Note: As mentioned, the only other way to get an Area Drop is from a chest. When you open a chest there is a 33% chance it will be gold, and a 67% chance it will be an Area Drop. This is the same for both regular chests and bonus chests.
Okay, but what IS an Area Drop? Every time you enter a new area (every 20 levels), the game will build a new pool consisting of items that could drop in your current area + level range. When you start a battle the current pool is adjusted to remove items that are no longer in your current level range. As you can imagine, this pool is constantly changing in size and makeup depending what level of the dungeon you are in. Most items drop in all dungeon areas, some are specific to just one or two. Every item in the game can have a min and max spawn level. Many have no max level (or else the dungeon would stop dropping items altogether)
Let’s say you’ve qualified for an Area Drop, and we have a pool of potential items to choose from. The game will now start picking random items from the pool, rolling for each one until one is successful. If for some reason the game makes 500 unsuccessful roll attempts, it will default to giving you the most common item available in the current pool. Each item has a different drop rate. Commons are usually around a 1/15 chance, uncommons 1/30, rares 1/100, and legendaries 1/1000 (and higher). Your item find stat simply reduces the denominator for these rolls. If your item find is 200, and the game has decided to randomly roll for a legendary with a 1/1000 chance, it will become a 1/800 chance.
Prior to 1.0.4, item find was applied to ALL item rolls. The problem becomes apparent pretty fast: If the game decides to roll for an item with a denominator less than or equal to your item find stat, you’ll always get it. So an item find of even 20 would guarantee you’d get every common the game ever tried to roll. With version 1.0.4 I implemented a quick solution: the item find stat would never be considered when rolling for common and uncommon items, meaning the game would have a lot more chances to roll rare and higher instead. In a sense the problem got passed along to rare items: with a high enough item find you’ll always get a rare item if the game decides to roll for it. However there are far fewer rares, so the problem is much less pronounced.
Original post from Shawn: Everything you ever wanted to know about drops
Keys are used to open locked Portals.
They are obtained from Minibosses and Bosses. Janitors will never drop keys as they cannot drop loot.
Locksmithing provides 1 key at the start of each run.
Ways to increase chance to find keys: