diff --git a/relay/config/dynamic_config.go b/relay/config/dynamic_config.go
index c358835..336a57e 100644
--- a/relay/config/dynamic_config.go
+++ b/relay/config/dynamic_config.go
@@ -7,49 +7,90 @@ import (
 	"os"
 	"path"
 	"strings"
+	"fmt"
 )
 
 // LoadDynamicConfig loads the dyanmic configuration for a bundle if
 // a) dynamic configuration is enabled and b) a config file exists for
-// the requested bundle
-func (c *Config) LoadDynamicConfig(bundle string) map[string]interface{} {
+// the requested bundle. Room- and user-specific configurations are
+// layered on top, if they exist.
+//
+// If any configuration files exist, but cannot be properly processed
+// (read, parsed as YAML, etc), an empty map is returned.
+func (c *Config) LoadDynamicConfig(bundle string, roomName string, userName string) map[string]interface{} {
 	retval := make(map[string]interface{})
 	if c.DynamicConfigRoot == "" {
 		log.Debugf("Dynamic config disabled.")
 		return retval
 	}
-	if fullPath := locateConfigFile(c.DynamicConfigRoot, bundle); fullPath != "" {
-		buf, err := ioutil.ReadFile(fullPath)
+
+	rootInfo, rootErr := os.Stat(c.DynamicConfigRoot)
+	if rootErr != nil || rootInfo.IsDir() == false {
+		log.Debugf("Dynamic configuration root dir not found.")
+		return retval
+	}
+
+	configs := allConfigFiles(c.DynamicConfigRoot, bundle, roomName, userName)
+	for _, f := range configs {
+		log.Debugf("Reading configuration file: %s", f)
+		buf, err := ioutil.ReadFile(f)
 		if err != nil {
-			log.Errorf("Reading dynamic config for bundle %s failed: %s.", bundle, err)
-			return retval
+			log.Errorf("Reading dynamic config file %s failed: %s.", f, err)
+			return make(map[string]interface{})
 		}
 
+		// by unmarshalling into the same map for each layer, we
+		// achieve a shallow merge of the layers, with successive
+		// top-level keys overwriting values previously set.
 		err = yaml.Unmarshal(buf, &retval)
 		if err != nil {
-			log.Errorf("Parsing dynamic config for bundle %s failed: %s.", bundle, err)
-			return retval
+			log.Errorf("Parsing dynamic config file %s failed: %s.", f, err)
+			return make(map[string]interface{})
 		}
-		for k := range retval {
-			if strings.HasPrefix(k, "COG_") || strings.HasPrefix(k, "RELAY_") {
-				delete(retval, k)
-				log.Infof("Deleted illegal key %s from dynamic config for bundle %s.", k, bundle)
-			}
+	}
+
+	for k := range retval {
+		if strings.HasPrefix(k, "COG_") || strings.HasPrefix(k, "RELAY_") {
+			delete(retval, k)
+			log.Infof("Deleted illegal key %s from dynamic config for bundle %s.", k, bundle)
 		}
 	}
+
 	return retval
 }
 
-func locateConfigFile(configRoot string, bundle string) string {
-	rootInfo, rootErr := os.Stat(configRoot)
-	if rootErr != nil || rootInfo.IsDir() == false {
-		log.Debugf("Dynamic configuration root dir not found.")
-		return ""
+// Given the config root, a bundle name, a Cog username, and a chat
+// room name, return a list of all the filenames to be consolidated,
+// in the order they should be layered.
+func allConfigFiles(configRoot string, bundle string, room string, user string) []string {
+	var configs []string
+
+	if path := resolveYAMLFile(path.Join(configRoot, bundle, "config")); path != "" {
+		configs = append(configs, path)
+	}
+
+	roomFile := fmt.Sprintf("room_%s", strings.ToLower(room))
+	if path := resolveYAMLFile(path.Join(configRoot, bundle, roomFile)); path != "" {
+		configs = append(configs, path)
+	}
+
+	userFile := fmt.Sprintf("user_%s", strings.ToLower(user))
+	if path := resolveYAMLFile(path.Join(configRoot, bundle, userFile)); path != "" {
+		configs = append(configs, path)
 	}
-	fullYamlPath := path.Join(configRoot, bundle, "config.yaml")
-	fullYmlPath := path.Join(configRoot, bundle, "config.yml")
+
+	return configs
+}
+
+// Given a base file name, return the path to either the yaml or yml
+// version, returning the ".yaml" version preferentially.
+func resolveYAMLFile(base string) string {
+
+	fullYamlPath := fmt.Sprint(base, ".yaml")
+
 	yamlInfo, yamlErr := os.Stat(fullYamlPath)
 	if yamlErr != nil || yamlInfo.IsDir() == true {
+		fullYmlPath := fmt.Sprint(base, ".yml")
 		ymlInfo, ymlErr := os.Stat(fullYmlPath)
 		if ymlErr != nil || ymlInfo.IsDir() == true {
 			log.Debugf("Dynamic config not found. Checked: '%s' and '%s'.",
diff --git a/relay/messages/env_builder.go b/relay/messages/env_builder.go
index fea32b0..e57d21f 100644
--- a/relay/messages/env_builder.go
+++ b/relay/messages/env_builder.go
@@ -41,7 +41,7 @@ func (er *ExecutionRequest) compileEnvironment(request *api.ExecRequest, relayCo
 
 	foundDynamicConfig := false
 	if useDynamicConfig {
-		dyn := relayConfig.LoadDynamicConfig(er.BundleName())
+		dyn := relayConfig.LoadDynamicConfig(er.BundleName(), er.Room.Name, er.User.Username)
 		foundDynamicConfig = len(dyn) > 0
 		for k, v := range dyn {
 			request.PutEnv(k, fmt.Sprintf("%s", v))