Loot table editor: a Summer App for game teams

Draft. Summer Apps is in a closed test. This page goes live after the end-to-end test on production.

What your team gets

One loot table at a time (pick it from a menu): every drop with its weight, quantity and rarity.
The real numbers: chance per roll (weight divided by the table’s total weight) and chance per kill or open (with the table’s number of rolls).
A pie chart of the table. Edit weights in place and save.
Your agent changes drops by asking (“halve the Moonfang chance from wolves”, “make the Ember Staff a 2% drop from the boss chest”).

Ask your agent

Loot table editor. Your agent builds, seeds and checks the app.

The manifest

{
  "name": "Loot tables",
  "purpose": "Drop weights and real drop chances for every loot table.",
  "permissions": ["data"],
  "collections": {
    "tables": {
      "description": "One loot table",
      "fields": {
        "name": { "type": "string", "required": true },
        "source": { "type": "string", "description": "The enemy or chest that rolls it" },
        "rolls": { "type": "integer", "required": true, "description": "Drops rolled per kill or open" }
      }
    },
    "drops": {
      "description": "One possible drop in a loot table",
      "fields": {
        "table": { "type": "string", "required": true, "description": "Record id of the loot table" },
        "item": { "type": "string", "required": true },
        "weight": { "type": "number", "required": true, "description": "Chance per roll = weight / sum of weights in the table" },
        "minQty": { "type": "integer" },
        "maxQty": { "type": "integer" },
        "rarity": { "type": "string", "description": "common, rare, epic or legendary" }
      }
    }
  },
  "agentTools": [
    {
      "name": "set_chance",
      "description": "Set one drop's weight so its chance per roll is exactly percent. Other weights stay. Returns the new weight and chances.",
      "input": {
        "type": "object",
        "properties": {
          "drop": { "type": "string", "description": "Record id of the drop" },
          "percent": { "type": "number", "exclusiveMinimum": 0, "exclusiveMaximum": 100 }
        },
        "required": ["drop", "percent"]
      }
    }
  ]
}

Seed the data

{
  "appId": "<app id>",
  "as": "seed",
  "ops": [
    { "op": "put", "collection": "tables", "recordId": "wolf", "data": { "name": "Grey Wolf", "source": "Grey Wolf", "rolls": 1 } },
    { "op": "put", "collection": "tables", "recordId": "boss-chest", "data": { "name": "Bell Keeper chest", "source": "Bell Keeper", "rolls": 3 } },
    { "op": "put", "collection": "drops", "recordId": "wolf-pelt", "data": { "table": "wolf", "item": "Wolf Pelt", "weight": 60, "minQty": 1, "maxQty": 2, "rarity": "common" } },
    { "op": "put", "collection": "drops", "recordId": "wolf-fang", "data": { "table": "wolf", "item": "Wolf Fang", "weight": 30, "minQty": 1, "maxQty": 1, "rarity": "common" } },
    { "op": "put", "collection": "drops", "recordId": "wolf-draught", "data": { "table": "wolf", "item": "Healing Draught", "weight": 9, "minQty": 1, "maxQty": 1, "rarity": "rare" } },
    { "op": "put", "collection": "drops", "recordId": "wolf-moonfang", "data": { "table": "wolf", "item": "Moonfang", "weight": 1, "minQty": 1, "maxQty": 1, "rarity": "legendary" } },
    { "op": "put", "collection": "drops", "recordId": "chest-gold", "data": { "table": "boss-chest", "item": "Gold Pouch", "weight": 50, "minQty": 20, "maxQty": 60, "rarity": "common" } },
    { "op": "put", "collection": "drops", "recordId": "chest-cloak", "data": { "table": "boss-chest", "item": "Moss Cloak", "weight": 30, "minQty": 1, "maxQty": 1, "rarity": "rare" } },
    { "op": "put", "collection": "drops", "recordId": "chest-staff", "data": { "table": "boss-chest", "item": "Ember Staff", "weight": 20, "minQty": 1, "maxQty": 1, "rarity": "epic" } }
  ]
}

Each table’s weights add up to 100 here, so a weight is the chance per roll in percent. That is not required: chances always come from the total.

An agent edit: “halve the Moonfang chance from wolves”

Read the drops:

{ "appId": "<app id>", "collection": "drops" }

In the answer, wolf-moonfang has "weight": 1 and a revision, here 1. Halve the weight:

{
  "appId": "<app id>",
  "ops": [
    { "op": "patch", "collection": "drops", "recordId": "wolf-moonfang", "patch": { "weight": 0.5 }, "ifRevision": 1 }
  ]
}

The Moonfang chance per wolf goes from 1% to about 0.5% (0.5 of 99.5). A conflict means someone changed the drop: read again and retry. For an exact chance, call the app’s tool while the person has it open: summer_app_call with { "tool": "set_chance", "input": { "drop": "chest-staff", "percent": 2 } }.

Check the look

After every publish:

summer_app_screenshot { "appId": "<app id>" }
summer_app_screenshot { "appId": "<app id>", "width": 390 }
summer_app_screenshot { "appId": "<app id>", "theme": "dark" }
summer_app_screenshot { "appId": "<app id>", "params": { "table": "boss-chest" } } if the app opens a table from launch params.

Check the chances by hand once: a wolf drops Wolf Pelt 60% per kill, and the boss chest (3 rolls) drops the Ember Staff 48.8% per open.

What it uses

SDK: summer.ready (its params for the starting table); summer.data.collection("tables") and summer.data.collection("drops") with .list(), .get(), .patch() and .subscribe(); summer.data.commands() to save table edits in one revision; summer.agent.tool("set_chance"); summer.page.declare() with a choice field for the table. Kit: summer-page; summer-section with summer-select in slot="aside" to pick the table; summer-stats and summer-stat (drops, rolls, the rarest drop’s chance per kill); summer-table (row-key="id", sortable; an editable weight column with format: "number"; chance columns with format: "percent" and digits: 1, which take a fraction from 0 to 1); summer-chart (kind="pie", x="item", y ["weight"]); summer-save-bar; summer-dialog with summer-form to add a drop. The chances, and the weight for an exact chance:

function chances(drops, rolls) {
  const total = drops.reduce((sum, d) => sum + d.weight, 0);
  return drops.map((d) => {
    const perRoll = total ? d.weight / total : 0;
    return { ...d, perRoll, perKill: 1 - (1 - perRoll) ** rolls };
  });
}
// The weight w that gives drop d a chance p, keeping the other weights: w = p * others / (1 - p)
summer.agent.tool("set_chance", async ({ drop, percent }) => {
  const drops = summer.data.collection("drops");
  const target = await drops.get(drop);
  if (!target) throw new Error(`No drop ${drop}`);
  const { records } = await drops.list({ limit: 500 });
  const others = records.filter((r) => r.data.table === target.data.table && r.recordId !== drop).reduce((sum, r) => sum + r.data.weight, 0);
  const p = percent / 100;
  const weight = Math.round((p * others / (1 - p)) * 1000) / 1000;
  await drops.patch(drop, { weight }, { ifRevision: target.revision });
  return { drop, weight };
});

Start here

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Essentials

Models

Using Summer

Summer Studio

Summer Apps

Other Engine Migration

Automation

Reference

Loot table editor: a Summer App for game teams

What your team gets

Ask your agent

The manifest

Seed the data

An agent edit: “halve the Moonfang chance from wolves”

Check the look

What it uses

​What your team gets

​Ask your agent

​The manifest

​Seed the data

​An agent edit: “halve the Moonfang chance from wolves”

​Check the look

​What it uses

What your team gets

Ask your agent

The manifest

Seed the data

An agent edit: “halve the Moonfang chance from wolves”

Check the look

What it uses