# Put a Stream Boss on your overlay

Let cheers, subscriptions, gifts and raids chip away at a boss; the knockout viewer becomes the next challenger.

Updated 27 September 2026

## Before you start

You need an [overlay in OBS](https://bloopbot.com/docs/widgets-in-obs). A Stream Boss is one layer on that overlay. The **Stream Boss** flow pack controls the fight; the layer reads its three [variables](https://bloopbot.com/docs/variables) and draws the result. The layer never awards damage by itself.

The pack starts with _The Boss_ at **1,000 / 1,000 HP**. Each bit cheered takes one HP, a new subscription takes 100 HP, a gifted-sub event takes 100 HP, and each raider takes one HP. You can change any damage amount by editing that pack member in **Flows**.

## 1. Install the Stream Boss flows

1. Open **Flows**, press **Add**, and press **Add** on the **Stream Boss** pack.
2. Review the three proposed channel variables — `boss_name`, `boss_hp`, `boss_max_hp` — and confirm the install. Keep their scope as **channel**; the layer reads one shared boss for everyone.
3. On your Flows page, open the pack to see its five members. New members start paused, so switch on the ones you want to run. **Boss: damage from cheers**, **subscriptions**, **gifted subs** and **raids** each do one job. **Boss: new challenger** starts with the **Boss defeated** trigger and crowns the viewer whose damage first takes HP to zero or below; keep that member on for the fight to continue.

> **Start with your own HP**
>
> Open **Variables** to change the starting name and HP values before the fight. Set `boss_hp` and `boss_max_hp` to the same positive number.

## 2. Add the Stream Boss layer

1. Open **Overlays** and the overlay you want to show during the fight.
2. Choose **Add** on the left, then drag **Stream Boss** from **Goals & games** onto the canvas, or open it and press **Add** to place it in the middle.
3. In **Content** → **Settings**, optionally choose a **Portrait image** and a transparent **Boss frame** from your media library. With no portrait image, the circle shows the current boss’s first letter. The chosen portrait image stays in place when the boss changes; change it here whenever you want different art.
4. Choose whether to **Show HP numbers**. The bar itself always shows the remaining fraction.
5. Press **Publish**. The live layer then follows the pack’s variables as viewers take part.

![The Stream Boss layer selected in the overlay editor: the canvas shows PixelPal with a partly filled HP bar, and the Content tab offers a portrait image, a boss frame and Show HP numbers.](https://bloopbot.com/docs/screenshots/stream-boss-layer.jpg)

_The Stream Boss layer selected in Studio, with portrait and HP controls in its Content tab beside a sample boss._

The editor’s preview shows _PixelPal_ at **650 / 1,000 HP** so you can place the layer even before the first real fight. This sample does not change your variables or reach Twitch. The published overlay shows your channel’s actual values.

## 3. Try a knockout

During a stream, a 250-bit cheer takes a default boss from 1,000 to 750 HP. Four such cheers take it to zero; the fourth cheerer becomes the new boss. Their HP refills and the maximum grows to 1,100. Later knockouts add another 100 to the maximum each time.

The bar flashes briefly when HP falls. The boss name and HP update as the variables change; you do not need to refresh OBS. The pack handles cheers, new subscriptions, gifted-sub events and incoming raids. A gifted-sub event takes 100 HP by default even if several subscriptions were gifted together.

![The published Stream Boss layer after a knockout: PixelPilot's portrait initial appears beside a full HP bar and 1,100 / 1,100 HP.](https://bloopbot.com/docs/screenshots/stream-boss-overlay.jpg)

_The published Stream Boss after a knockout, with PixelPilot as the challenger and a full 1,100 HP bar._

## React to a knockout

**Boss defeated** is a trigger in the flow editor’s node library, under **Overlay**. It runs once each time the boss’s HP reaches zero or below: the hit that takes it from above zero, never the hits that land on a boss already down. The pack’s **Boss: new challenger** uses it, and you can start your own flows from it too.

Its tokens:

- `$(user)` — the viewer who landed the knockout. It is blank when nobody can be named, for example an anonymous gift.
- `$(boss)` — the name of the boss that was defeated, before the new challenger takes over.
- `$(maxhp)` — that boss’s maximum HP.

For example, to celebrate in chat:

1. In **Flows**, create a flow and pick **Boss defeated** as its trigger.
2. Add **Chat message** after it with `$(user) defeated $(boss) and all $(maxhp) HP!`
3. Save and switch the flow on.

When a 250-bit cheer from PixelPilot knocks out a 1,000 HP _The Boss_, chat reads _PixelPilot defeated The Boss and all 1000 HP!_ Use **Test fire** in the flow editor to try it on a sample knockout: it is a dry run, so nothing reaches chat or Twitch and no variable changes.

Boss defeated needs the pack’s `boss_hp` variable, and only a flow’s damage can land a knockout. Setting `boss_hp` to zero yourself under **Variables** does not run it.

## Style the layer

Use **Parts** to style the **Panel**, **Portrait**, **Boss name**, **HP track**, **HP fill** and **HP numbers** separately ([Style one part at a time](https://bloopbot.com/docs/widget-themes#parts)). Your overlay’s custom CSS can also use `.w-boss-panel`, `.w-boss-portrait`, `.w-boss-name`, `.w-boss-track`, `.w-boss-fill` and `.w-boss-readout`.

## If something looks wrong

- The live layer says _No boss yet_: install the **Stream Boss** pack and check that its `boss_name`, `boss_hp` and `boss_max_hp` variables are declared for the channel.
- A cheer does not move the bar: check that **Boss: damage from cheers** is on in **Flows**, and that the published overlay is the one you added the layer to.
- A **Boss defeated** flow did not run: check it is switched on, and that HP went from above zero to zero or below through a damage flow. A boss already at zero has to be refilled before it can be defeated again.
- The new boss says _Anonymous_: the knockout came from an anonymous gift, so there is no viewer name to show. You can set `boss_name` under **Variables** if you want a different name.
- The bar stays empty or full: check that `boss_max_hp` is a positive number and `boss_hp` is a number. If you changed their starting values, reset or set the current values too.
- The portrait does not change with the name: the portrait file is artwork you picked in **Content** → **Settings**. Leave it empty for an initial that follows the name.