# Playtesting

> Play the game in the tab with test players, read the Play log and live values, and fix problems first.

## Play

![Pressing Play, joining Red, starting the match, adding a test player and moving around.](/shots/play-match.mp4)

1. Press **Play**. The game runs in the tab, with you as the room owner.
2. Pick a team in the Menu and press **Start**.
3. Click the game, then move with the arrow keys or WASD.
4. Press **Stop** to go back to editing.

## Test players

In **Players**, press **Add player**. Each one can stand still, hold a
direction or follow the mouse. You can also drive them or watch from their view.

You hear the game's sounds as the player you watch hears them: a sound
**near** someone else, or fading with distance, sounds as it would to them.
Sound starts once you click or press a key in the tab.

## See what happens

- **Play log**: joins, chat, events and row errors (click one to jump to the row).
- **Variables**: select one to see its value right now.
- **Physics view**: turn it on in the match bar to see every disc, wall,
  crossing and joint as disko moves them, over the game's look.

## Problems

![The Problems panel listing two unfilled slots.](/shots/problems-panel.png)

The Studio checks your game as you edit:

- **Errors** stop Play and Publish. Click one to jump to it.
- **Warnings** don't.

Every problem explained: [Errors](/errors#studio-problems).