Rarity levels for Loot.

How are the rarity levels determined?

The rarity level of any given item is deducted from its number of occurrences in the total number of Loot items.

Rarity level	Description	Occurrences
Level 1	Common items appear 375 or more times.	47.25% - 30,237 items
Level 2	Uncommon items appear less than 375 times.	12.61% - 8,073 items
Level 3	Rare items appear less than 358 times.	11.78% - 7,537 items
Level 4	Epic items appear less than 101 times.	10.29% - 6,587 items
Level 5	Legendary items appear less than 10 times.	9.67% - 6,189 items
Level 6	Mythic items appear exactly 1 time.	8.4% - 5,377 items

Installation

npm i --save loot-rarity # npm
yarn add loot-rarity # yarn
pnpm add loot-rarity # pnpm

API

Types

// RarityLevel goes from 1 (common) to 6 (mythic). See table above for more info.
type RarityLevel = 1 | 2 | 3 | 4 | 5 | 6;

// ColorFn allows to override a color in different places.
type ColorFn = (colorParameters: {
  level: RarityLevel; // the rarity level
  color: string; // the base color you can override
  itemName?: string; // in certain cases the item name will be present
}) => string | void | null; // return a string to override the color

itemRarity()

function itemRarity(itemName: string): RarityLevel;

This function returns the rarity level of an item, given its name.

Example:

let rarity = itemRarity('"Golem Roar" Studded Leather Belt of Fury');

console.log(rarity); // 6

rarityColor()

function rarityColor(
  itemOrRarityLevel: string | RarityLevel,
  options?: { colorFn: ColorFn }
): string;

This function returns the color of a rarity level, given an item name or a rarity level.

Example:

let color = rarityColor("Ornate Belt of Perfection");

console.log(color); // "#c13cff"

rarityDescription()

function rarityDescription(itemOrRarityLevel: string | RarityLevel): string;

This function returns the description of a rarity level, given an item name or a rarity level.

Example:

let levelA = rarityDescription(1);
let levelB = rarityDescription("Studded Leather Boots of Rage");

console.log(levelA); // "Common"
console.log(levelB); // "Legendary"

rarityImage()

function rarityImage(
  imageOrItems: string | string[],
  options?: {
    colorFn?: ColorFn;
    displayLevels?: Boolean;
    imageFormat: "data-uri" | "svg";
  }
): Promise<string>;

This function generates an image with added rarity levels.

It accepts any of the following:

• SVG source of a Loot image.
• An array of Loot items.
• Data URI representing a Loot image.
• Data URI representing a Loot metadata (as returned by the tokenURI() method of the Loot contract).
• HTTP URL pointing to a Loot image.

Options:

• colorFn allows to override the color of a particular item.
• displayLevels allows to add levels to the items list.
• imageFormat controls the output: data URI ("data-uri") (default) or SVG source ("svg").

Example with React, use-nft to load the image, and swr to handle the async function:

import { rarityImage } from "loot-rarity";
import { useNft } from "use-nft";
import useSWR from "swr";

function Loot({ tokenId }) {
  const { nft } = useNft(LOOT, id);
  const { data: image } = useSWR(nft?.image, rarityImage);
  return image ? <img src={image} /> : <div>Loading…</div>;
}

The resulting images could look like this:

Default

let image = await rarityImage(image);

With the rarity levels displayed

let rarified = await rarityImage(image, { displayLevels: true });

With custom colors

let rarified = await rarityImage(image, {
  colorFn: ({ itemName }) => itemName?.includes("Slippers") && "cyan",
});

rarityImageFromItems()

function rarityImageFromItems(
  items: string[],
  options: {
    colorFn?: ColorFn;
    displayLevels?: Boolean;
    imageFormat: "data-uri" | "svg";
  }
): string;

This function is similar to rarityImage, except it only accepts an array of items. It is useful when you already have a list of items, because it returns a string directly (while rarityImage() returns a Promise resolving to a string).

Options:

• colorFn allows to override the color of a particular item.
• displayLevels allows to add levels to the items list.
• imageFormat controls the output: data URI ("data-uri") (default) or SVG source ("svg").

Example:

import { rarityImageFromItems } from "loot-rarity";

const bag = [
  "Grimoire",
  '"Woe Bite" Ornate Chestplate of the Fox +1',
  "Silk Hood",
  "Heavy Belt of Fury",
  "Shoes",
  "Silk Gloves",
  '"Rune Glow" Amulet of Rage',
  "Silver Ring",
];

document.body.innerHTML = `
  <img src=${rarityImageFromItems(bag)} />
`;

Demo app

Have a look at the demo app to see how it works.

You can also run it from this repository (see demo/):

# Install pnpm if needed
npm i -g pnpm

# Build loot-rarity
pnpm i
pnpm build

# Run the demo app
cd demo
pnpm i
pnpm dev

Thanks

• @scotato for github.com/scotato/inventory, loot-rarity was heavily inspired by it.
• @Anish-Agnihotri for the data he extracted from Loot and that loot-rarity is using.

License

MIT