A simple and flexible loot rolling system.
npm i lootastic
You can create a LootTable with:
- a plain array (all item weights will be set to 1)
- an array with objects formatted like
{ chance: X, result: <item> }
You can also pass in arollModifier into the options object to increase the weights of every item.
Examples:
// plain initialization - all weights are 1let lootTable = new LootTable(['sword', 'armor', 'potion', 'shield']);// weight initialization - swords are common, potions are notlet lootTable = new LootTable([ { chance: 1, result: 'potion' }, { chance: 5, result: 'armor' }, { chance: 10, result: 'shield' }, { chance: 20, result: 'sword' }]);// weight initialization with a rollModifier - each weight is 10 higher// a common use-case here is a "luck bonus" in item dropslet lootTable = new LootTable([ { chance: 1, result: 'potion' }, { chance: 5, result: 'armor' }, { chance: 10, result: 'shield' }, { chance: 20, result: 'sword', maxChance: 100 }, // always a 1/5 drop rate { chance: -1, result: 'gold' } // always drops], { rollModifier: 10 });
You can roll a table using one of 3 methods:
- choose X items with replacement
- choose X items without replacement
- try to roll for each item in the table using a chance/X probability (where X would be something like 1/10000)
Examples:
let result = lootTable.chooseWithReplacement(1) // 1 random item + goldlet result = lootTable.chooseWithReplacement(5) // 5 random items + goldlet result = lootTable.chooseWithoutReplacement(1) // 1 random item + goldlet result = lootTable.chooseWithoutReplacement(4) // the whole table + goldlet result = lootTable.chooseWithoutReplacement(5) // error - not enough items to chooselet result = lootTable.tryToDropEachItem(1) // all items will drop + goldlet result = lootTable.tryToDropEachItem(10) // shield and sword will guaranteed drop + goldlet result = lootTable.tryToDropEachItem(100) // some items might drop + gold
If you want to roll multiple loot tables at once, or the same loot table multiple times (suppose you have a monster drop table and a zone drop table), you can use the LootRoller class:
let result = LootRoller.rollTables([ { table: lootTable, func: LootFunctions.WithoutReplacement, args: 1 }, // always picks 1 item (+ gold) { table: lootTable, func: LootFunctions.EachItem, args: 1 }, // try to drop each item (+ gold)]); // 2 gold entries, 1 item, and maybe more depending on the EachItem roll
- You can add a property
maxChance to an item to customizetryToDropForEachItem when you don't want to scale item probabilities. - You can specify a weight of -1 to tell an item to always drop in addition to other random drops.
- Use plain objects, not classes, since the data is cloned when rolling loot.