# Tutorial: Create a matchmaking rule set
<a name="match-create-ruleset"></a>

Before you create a matchmaking rule set for your Amazon GameLift Servers FlexMatch matchmaker, we recommend checking the [rule set syntax](match-rules-reference.md). After you create a rule set using the Amazon GameLift Servers console or the Amazon Command Line Interface (Amazon CLI), you can't change it.

Note that there is a [service quota](https://console.amazonaws.cn/servicequotas/home/services/gamelift/quotas/) for the maximum number of rule sets that you can have in an Amazon Region, so it's a good idea to delete unused rule sets.

**Topics**

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#### [ Console ]

**Create a rule set**

1. Open the Amazon GameLift Servers console at [https://console.amazonaws.cn/gamelift/](https://console.amazonaws.cn/gamelift/).

1. Switch to the Amazon Region where you want to create your rule set. Define rule sets in the same Region as the matchmaking configuration that uses them.

1. In the navigation pane, choose **FlexMatch**, **Matchmaking rule sets**.

1. On the **Matchmaking rule sets** page, choose **Create rule set**.

1. On the **Create matchmaking rule set** page, do the following:

   1. Under **Rule set settings**, for **Name**, enter a unique descriptive name that you can use to identify it in a list or in events and metrics tables.

   1. For **Rule set**, enter your rule set in JSON. For information about designing a rule set, see [Design a FlexMatch rule set](match-design-ruleset.md). You can also use one of the example rule sets from [FlexMatch rule set examples](match-examples.md).

   1. Choose **Validate** to verify that the syntax of your rule set is correct. You can't edit rule sets after they're created, so it's a good idea to validate them first.

   1. (Optional) Under **Tags**, add tags to help you manage and track your Amazon resources.

1. Choose **Create**. If creation is successful, you can use the rule set with a matchmaker.

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#### [ Amazon CLI ]

**Create a rule set**

Open a command line window and use the command [create-matchmaking-rule-set](https://docs.amazonaws.cn/cli/latest/reference/gamelift/create-matchmaking-rule-set.html).

This example command creates a simple matchmaking rule set that sets up a single team. Be sure to create the rule set in the same Amazon Region as the matchmaking configurations that uses it.

```
aws gamelift create-matchmaking-rule-set \
    --name "SampleRuleSet123" \
    --rule-set-body '{"name": "aliens_vs_cowboys", "ruleLanguageVersion": "1.0", "teams": [{"name": "cowboys", "maxPlayers": 8, "minPlayers":  4}]}'
```

If the creation request is successful, Amazon GameLift Servers returns a [MatchmakingRuleSet](https://docs.amazonaws.cn/gameliftservers/latest/apireference/API_MatchmakingRuleSet.html) object that includes the settings that you specified. A matchmaker can now use the new rule set.

------<a name="match-delete-ruleset"></a><a name="match-delete-ruleset-cli"></a>

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#### [ Console ]

**Delete a rule set**

1. Open the Amazon GameLift Servers console at [https://console.amazonaws.cn/gamelift/](https://console.amazonaws.cn/gamelift/).

1. Switch to the Region that you created the rule set in.

1. In the navigation pane, choose **FlexMatch**, **Matchmaking rule sets**.

1. On the **Matchmaking rule sets** page, select the rule set that you want to delete, and then choose **Delete**.

1. In the **Delete rule set** dialog box, choose **Delete** to confirm deletion.
**Note**  
If a matchmaking configuration is using the rule set, Amazon GameLift Servers displays an error message (**Can't delete rule set**). If this occurs, change the matchmaking configuration to use a different rule set, then try again. To find out which matchmaking configurations are using a rule set, choose the name of a rule set to view its details page.

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#### [ Amazon CLI ]

**Delete a rule set**

Open a command line window and use the command [delete-matchmaking-rule-set](https://docs.amazonaws.cn/cli/latest/reference/gamelift/delete-matchmaking-rule-set.html) to delete a matchmaking rule set.

If a matchmaking configuration is using the rule set, Amazon GameLift Servers returns an error message. If this occurs, change the matchmaking configuration to use a different rule set, then try again. To get a list of which matchmaking configurations are using a rule set, use the command [describe-matchmaking-configurations](https://docs.amazonaws.cn/cli/latest/reference/gamelift/describe-matchmaking-configurations.html) and specify the rule set name.

This example command checks for the matchmaking rule set's usage and then deletes the rule set.

```
aws gamelift describe-matchmaking-rule-sets \
    --rule-set-name "SampleRuleSet123" \
    --limit 10

aws gamelift delete-matchmaking-rule-set \
    --name  "SampleRuleSet123"
```

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