Running a Multiplayer Game

Let several people play one simulation together, each on their own device, with you as the facilitator.

In a step-by-step game one person makes every decision. A multiplayer game shares them out: each player takes a role, decides for that role on their own phone or laptop, and the round closes once everyone has decided. You run the session as the facilitator.

Try it: the Beer Distribution Game

The Beer Distribution Game template has a dashboard called Multiplayer Game with one order input for each of the four stages: retailer, wholesaler, distributor and brewery.

1. Open the Multiplayer Game dashboard and click Game in the top bar. The Game session panel opens.
2. Under Who plays each role?, choose Human or Model policy for each stage. The model plays a stage set to Model policy with its own ordering rule, so two people can play a four-stage game.
3. Click Create session. You get a Session code and one join link per human role. Copy each link and send it to a player.
4. When everyone has joined, click Start game.

What players do

Players need no Metapad account. They open their link, enter Your name, confirm their role and click Join. Until you start, they see Waiting for the facilitator to start the game.

During the game each player sees the dashboard with their own role's numbers, types their decision and clicks Submit. Their screen then says Submitted — waiting for the others. Your numbers lists their latest results. When the last round is played they see Game over.

Running the rounds

While the panel is open you see the whole game: every stage's numbers on the dashboard, and Waiting on, the players who haven't submitted yet. A round closes by itself once everyone has submitted.

• Force next round closes the round without the missing players. For them the model's policy decides; where a role has no policy, the player's last decision is repeated.
• End game stops the session early.

When the game ends, charts set to Hide until the end appear for everyone. That is your debrief: the whole supply chain, round by round.

Closing the panel doesn't stop the game. Click Game again to pick it back up.

Turning your own dashboard into a multiplayer game

Start from a playable dashboard (see Playing Through a Simulation Step by Step), then:

1. One input per role. Each agent that a Round decision input writes to becomes a role. In the Beer Game each stage's order input writes to that stage, so there are four roles.
2. Let the model stand in (optional). In the input's properties, Active can name a yes/no property of the agent. Metapad uses it to switch between a human player and the model's own rule. A role without one is always played by a person.
3. Switch it on. Select the Round control and tick Played as a game. Only then does the Game button appear in the top bar.

Each player only sees the numbers of their own role and of what flows into it directly, such as their incoming orders and deliveries. Value tiles set to Show the round being decided show the start of the current round, so players can decide from what they would really know.

Other players' inputs. By default a player sees only their own input; the other roles' inputs are left off their screen. To share a role's decisions, select its input and tick Visible to other players (shown once the round control is played as a game). The other players then see that decision read-only, as soon as the round has closed, never while it is still open. Playing the same game once with hidden and once with visible orders is a good way to show what transparency does to a supply chain.

Good to know

• Hosting a game needs the Team plan and edit access to the model. A team can start 50 sessions a month; the Game session panel shows how many have been used this month. Higher plans have no monthly limit. A session counts once you click Start game; one ended before its first round closes doesn't count. Readers of a published site can play the single-player version but cannot start a session.
• A session plays on its own copy of the settings. Nothing players decide is written into your model.

Next steps

• Playing Through a Simulation Step by Step: the single-player version and the round control
• Adding Charts, Sliders, and Checkboxes: the widgets a game dashboard is built from