diff --git a/cmd/gbrgames/boottest.go b/cmd/gbrgames/boottest.go
index 2b6167e..7ad80b4 100644
--- a/cmd/gbrgames/boottest.go
+++ b/cmd/gbrgames/boottest.go
@@ -119,6 +119,7 @@ func runBootTestPayload(args []string) error {
 		"configFormatOptions": g["configFormatOptions"],
 		"startupCommand":      g["defaultStartupCommand"],
 		"memoryLimitMb":       g["requiredMemoryMb"],
+		"containerUser":       g["containerUser"],
 		"dockerNetwork":       bootTestNetwork,
 		"logFilePath":         g["logFilePath"],
 		"readyPattern":        g["readyPattern"],
diff --git a/cmd/gbrgames/import.go b/cmd/gbrgames/import.go
index 5ad9848..79da1d5 100644
--- a/cmd/gbrgames/import.go
+++ b/cmd/gbrgames/import.go
@@ -18,7 +18,7 @@ import (
 // (enabled, allowPaidHosting, allowPrivateHosting, imageUrl) are deliberately left out.
 var gameFields = []string{
 	"id", "name",
-	"defaultDockerImage", "defaultStartupCommand", "requiredMemoryMb", "requiredDiskMb", "defaultPorts",
+	"defaultDockerImage", "containerUser", "defaultStartupCommand", "requiredMemoryMb", "requiredDiskMb", "defaultPorts",
 	"installMethod", "installConfig",
 	"defaultConfig", "configSchema", "configFilePath", "configFileFormat", "configFormatOptions",
 	"agnosticCommandConfig", "clusterConfig",
diff --git a/games/ark-survival-ascended-crossplay/game.yaml b/games/ark-survival-ascended-crossplay/game.yaml
index e34b705..06038f9 100644
--- a/games/ark-survival-ascended-crossplay/game.yaml
+++ b/games/ark-survival-ascended-crossplay/game.yaml
@@ -2,7 +2,8 @@
 id: ark-survival-ascended-crossplay
 name: 'ARK: Survival Ascended (Crossplay Dedicated Server)'
 defaultDockerImage: mschnitzer/asa-linux-server:latest
-defaultStartupCommand: bash -c 'mkdir -p /server /data/Steam /data/steamcmd /data/cluster-shared && rm -rf /home/gameserver/server-files /home/gameserver/Steam /home/gameserver/steamcmd /home/gameserver/cluster-shared && ln -sfn /server /home/gameserver/server-files && ln -sfn /data/Steam /home/gameserver/Steam && ln -sfn /data/steamcmd /home/gameserver/steamcmd && ln -sfn /data/cluster-shared /home/gameserver/cluster-shared && export ASA_START_PARAMS="${ASA_START_PARAMS:-${SERVER_MAP:-TheIsland_WP}?listen?Port=${PORT:-7777}?RCONPort=${RCON_PORT:-27020}?RCONEnabled=True -WinLiveMaxPlayers=${MAX_PLAYERS:-70} -ServerPlatform=ALL}" && exec /usr/bin/start_server'
+containerUser: "25000:25000"
+defaultStartupCommand: bash -c 'mkdir -p /server /data/Steam /data/steamcmd /data/cluster-shared && rm -rf /home/gameserver/server-files /home/gameserver/Steam /home/gameserver/steamcmd /home/gameserver/cluster-shared && ln -sfn /server /home/gameserver/server-files && ln -sfn /data/Steam /home/gameserver/Steam && ln -sfn /data/steamcmd /home/gameserver/steamcmd && ln -sfn /data/cluster-shared /home/gameserver/cluster-shared && export ASA_START_PARAMS="${ASA_START_PARAMS:-${SERVER_MAP:-TheIsland_WP}?listen?Port=${PORT:-7777}?RCONPort=${RCONPORT:-27020}?RCONEnabled=True -WinLiveMaxPlayers=${MAX_PLAYERS:-70} -ServerPlatform=ALL}" && exec /usr/bin/start_server'
 requiredMemoryMb: 16384
 requiredDiskMb: 32768
 defaultPorts:
diff --git a/games/ark-survival-ascended-crossplay/test.yaml b/games/ark-survival-ascended-crossplay/test.yaml
index 1b49f91..f3ff373 100644
--- a/games/ark-survival-ascended-crossplay/test.yaml
+++ b/games/ark-survival-ascended-crossplay/test.yaml
@@ -1,3 +1,6 @@
 # yaml-language-server: $schema=../../schema/test.schema.json
 # Values CI uses to boot-test this game. Never put real credentials here: map them under 'secrets'.
-timeoutSec: 900
+# No readyPattern yet: the server must stay up for 10 minutes, which covers the ~13 GB first
+# download and Proton's slow first start.
+settleSec: 600
+timeoutSec: 2400
diff --git a/schema/game.schema.json b/schema/game.schema.json
index 1287166..7ba4bf9 100644
--- a/schema/game.schema.json
+++ b/schema/game.schema.json
@@ -16,6 +16,11 @@
     "name": { "description": "Display name shown to users.", "type": "string", "minLength": 1 },
 
     "defaultDockerImage": { "description": "Image the game server runs in.", "type": "string", "minLength": 1 },
+    "containerUser": {
+      "description": "uid:gid the server runs as, for images built around their own user (ARK's needs 25000:25000). Defaults to 1000:1000; root is never allowed.",
+      "type": ["string", "null"],
+      "pattern": "^[1-9][0-9]{0,8}:[1-9][0-9]{0,8}$"
+    },
     "defaultStartupCommand": { "description": "Command run inside the container. May use config placeholders.", "type": ["string", "null"] },
     "requiredMemoryMb": { "type": ["integer", "null"], "minimum": 128 },
     "requiredDiskMb": { "type": ["integer", "null"], "minimum": 128 },