Every MU Online event on MUOnline.ai, counted down in your own timezone. Castle Siege runs every Saturday from 21:00 to 22:00 UTC on both the Permanent Realm and the Speed Realm Autumn Edition.
Blood Castle opens 22 times a day, and Chaos Castle, Crywolf, Boss Battle Together, Arca War and Icewind Valley follow fixed UTC times read from the server's event files.
Events are sorted by the next start time. Cards below are shown in your selected timezone, with live and registering events highlighted.
Time left until registration opens for each event on each realm. A gold cell means registration is open now and counts down to the start.
| Event | Permanent Realm | Speed Realm Autumn Edition |
|---|---|---|
| Icewind Valley | --:--:-- | --:--:-- |
| Boss Battle Together | --:--:-- | --:--:-- |
| Chaos Castle | --:--:-- | --:--:-- |
| Blood Castle | --:--:-- | --:--:-- |
| Crywolf | --:--:-- | --:--:-- |
| Arca War | --:--:-- | --:--:-- |
| Castle Siege | --:--:-- | --:--:-- |
Every start time below is read from the server's event files. Server time is UTC; the CEST column is Central European time, which is UTC+2 (CEST) until the last Sunday of October and UTC+1 (CET) after it.
| Event | Realm | Days | Start (UTC) | Start (CEST) | Duration | Entry rules |
|---|---|---|---|---|---|---|
| Castle Siege | Permanent Realm | Saturday (weekly) | 21:00 | 23:00 | 60 min | Guild vs guild. Guild master registers during the registration stage, which opens on cycle day 0 at 16:00 UTC (Sunday in this schedule). |
| Castle Siege | Speed Realm Autumn Edition | Saturday (weekly) | 21:00 | 23:00 | 60 min | Guild vs guild. Guild master registers during the registration stage, which opens on cycle day 0 at 16:00 UTC (Sunday in this schedule). |
| Blood Castle | Both realms | Every day | 00:10, 00:40, 01:10, 01:40, 02:10, 02:40, 03:10, 03:40, 05:10, 07:10, 09:10, 11:10, 13:10, 15:10, 17:10, 19:10, 21:10, 21:40, 22:10, 22:40, 23:10, 23:40 | 02:10, 02:40, 03:10, 03:40, 04:10, 04:40, 05:10, 05:40, 07:10, 09:10, 11:10, 13:10, 15:10, 17:10, 19:10, 21:10, 23:10, 23:40, 00:10, 00:40, 01:10, 01:40 | 15 min | Gate opens 5 min before each start. Level brackets: 50–399, 400–799, 800–899, 900–1099, 1100–1299, 1300–1499, 1500+. |
| Chaos Castle | Both realms | Every day | 01:00, 15:00, 17:00, 19:00, 21:00, 23:00 | 03:00, 17:00, 19:00, 21:00, 23:00, 01:00 | 15 min | Entry opens at the listed time; the fight starts 5 min later. Level brackets: 50–399, 400–799, 800–899, 900–1099, 1100–1299, 1300–1499, 1500+. |
| Crywolf | Both realms | Every day | 02:10, 05:10, 08:10, 11:10, 14:10, 17:10, 20:10, 23:10 | 04:10, 07:10, 10:10, 13:10, 16:10, 19:10, 22:10, 01:10 | 15 min battle | No registration; the Balgass invasion is fought in Crywolf Fortress. |
| Boss Battle Together | Both realms | Every day | 00:15, 04:15, 08:15, 12:15, 16:15, 20:15 | 02:15, 06:15, 10:15, 14:15, 18:15, 22:15 | 5 min | Entry opens 5 min before the start. Max 100 players per round. |
| Arca War | Permanent Realm | Mon, Wed, Fri, Sat | 00:00, 08:00, 14:00, 20:00 | 02:00, 10:00, 16:00, 22:00 | 10 min | Guilds with at least 10 members. Guild master registers first (5 min), members follow (5 min). |
| Arca War | Speed Realm Autumn Edition | Mon, Wed, Fri, Sat | 01:00, 07:00, 13:00, 19:00 | 03:00, 09:00, 15:00, 21:00 | 10 min | Guilds with at least 10 members. Guild master registers first (5 min), members follow (5 min). |
| Icewind Valley | Permanent Realm | Every day | 07:30, 19:30 | 09:30, 21:30 | 60 min | Guilds of 10–50 members. Guild master types /regicewind in the 5-min registration window before each start. |
| Icewind Valley | Speed Realm Autumn Edition | Every day | 00:30, 03:30, 06:30, 09:30, 12:30, 15:30, 18:30, 21:30 | 02:30, 05:30, 08:30, 11:30, 14:30, 17:30, 20:30, 23:30 | 60 min | Guilds of 10–20 members. Guild master types /regicewind in the 5-min registration window before each start. |
| Event | No VIP – VIP5 | VIP6 | VIP7+ |
|---|---|---|---|
| Chaos Castle | 2 | 3 | 4 |
| Blood Castle | 5 | 6 | 7 |
| Devil Square | 5 | 6 | 7 |
| Imperial Fort | 2 | 3 | 4 |
| Illusion Temple | 2 | 3 | 4 |
| Doppelganger | 3 | 4 | 5 |
| Boss Battle Together | 2 | 3 | 4 |
Entries per account and day. Events that appear here but not in the schedule above have no timetable in the server's event files, so only their entry limits are listed.
Blood Castle, Chaos Castle, Crywolf, Boss Battle Together and Castle Siege share one schedule; only the guild events differ, so set the realm switch on the countdown cards to the realm you play.
| Event | Permanent Realm (5000x EXP) | Speed Realm Autumn Edition (99,999x EXP) |
|---|---|---|
| Arca War (Mon, Wed, Fri, Sat) | 00:00, 08:00, 14:00, 20:00 UTC | 01:00, 07:00, 13:00, 19:00 UTC |
| Icewind Valley (daily) | 07:30 and 19:30 UTC (2x a day) | Every 3 hours from 00:30 UTC (8x a day) |
| Icewind Valley guild size | 10 to 50 members | 10 to 20 members |
The battle starts every Saturday at 21:00 UTC (23:00 CEST) and ends at 22:00 UTC on both realms.
The server runs a 7-day cycle. The site's schedule maps cycle day 0 to Sunday, which gives this week:
| Stage | Starts (UTC) |
|---|---|
| Guild registration | Sunday 16:00 |
| Sign of Lord registration | Thursday 00:00 |
| Attacking guilds announced | Friday 00:00 |
| Siege battle | Saturday 21:00-22:00 |
| Cycle ends, next registration | Sunday 16:00 |
As in Webzen's rules:
Webzen's rules also ask for a guild of 20 or more members.
As in Webzen's game, attackers hold the crown switches so their guild master can reach the crown and register the Seal. On MUOnline.ai any guild member can operate a crown switch, only the guild master can use the crown, and friendly fire is off during the siege.
Under Webzen's rules, the winning guild master becomes Lord of MU, with access to the Land of Trials and control of the merchant tax. On this server the castle Lord Mix is limited to the guild master, once a day. Join Discord through the community page for siege announcements, and check guild standings on the Permanent Realm ranking or the Speed Realm ranking. For tactics, read the Castle Siege guide.
03:10, 03:40, then every two hours from 05:10 to 21:10, then every 30 minutes from 21:40 to 02:40. The gate opens five minutes before each start and a run lasts 15 minutes. Each player needs 200 monster kills, and a team can finish early once 60 seconds have passed.
| Blood Castle | Character level |
|---|---|
| BC1 | 50-399 |
| BC2 | 400-799 |
| BC3 | 800-899 |
| BC4 | 900-1099 |
| BC5 | 1100-1299 |
| BC6 | 1300-1499 |
| BC7 | 1500 and up |
Standard accounts enter Blood Castle five times a day, VIP6 six times and VIP7 or higher seven times. You need the event's entry item; check the item database before the gate opens.
Chaos Castle starts at 01:00, 15:00, 17:00, 19:00, 21:00 and 23:00 UTC. Entry opens five minutes before the start and the fight lasts 15 minutes. Daily entries: 2 standard, 3 for VIP6, 4 for VIP7 and higher.
Crywolf starts eight times a day, every three hours from 02:10 UTC, on both realms.
Boss Battle Together runs at 00:15, 04:15, 08:15, 12:15, 16:15 and 20:15 UTC. Entry opens five minutes early, a 30-second countdown follows, and the fight lasts five minutes with room for 100 players. Daily entries follow the same 2 / 3 / 4 split as Chaos Castle.
Arca War runs on Monday, Wednesday, Friday and Saturday. A guild needs at least 10 members. The guild master registers first, members have five minutes to follow, and each round lasts 10 minutes. The tower buff adds 20% EXP.
On both realms the guild master types /regicewind in the five-minute window before the start, and each round lasts 60 minutes. The event config holds separate reward bags for guild masters and guild members. The 99,999x seasonal realm is built for a short season, so Icewind Valley runs there far more often (8x a day against 2x on the Permanent Realm).
Castle Siege is fought every Saturday from 21:00 to 22:00 UTC (23:00 to 00:00 CEST) on both the Permanent Realm and the Speed Realm Autumn Edition. It lasts 60 minutes. The site's schedule opens registration on Sunday at 16:00 UTC.
As in Webzen's rules, your guild master registers the guild at the Castle Siege NPC in the Valley of Loren during the registration stage, then the guild hands in Signs of Lord to raise its rank. The top-ranked guilds attack the castle owner on Saturday. Webzen's rules also ask for 20 or more guild members.
22 times a day on each realm: 03:10, 03:40, every two hours from 05:10 to 21:10, and every 30 minutes from 21:40 to 02:40 UTC. Standard accounts enter five times a day, VIP6 six times and VIP7 or higher seven times.
Both use seven brackets: 1 for levels 50-399, 2 for 400-799, 3 for 800-899, 4 for 900-1099, 5 for 1100-1299, 6 for 1300-1499 and 7 from level 1500. Chaos Castle starts at 01:00, 15:00, 17:00, 19:00, 21:00 and 23:00 UTC.
A guild with at least 10 members. Arca War runs Monday, Wednesday, Friday and Saturday at 01:00, 07:00, 13:00 and 19:00 UTC on the Speed Realm Autumn Edition and at 00:00, 08:00, 14:00 and 20:00 UTC on the Permanent Realm. Members have five minutes to join after the guild master registers; each round lasts 10 minutes.
On the Speed Realm Autumn Edition it starts every three hours from 00:30 UTC for guilds of 10 to 20 members; on the Permanent Realm at 07:30 and 19:30 UTC for guilds of 10 to 50. The seasonal 99,999x realm is built for a short season, so Icewind Valley runs there far more often (8x a day against 2x on the Permanent Realm).
Blood Castle, Chaos Castle, Crywolf, Boss Battle Together and Castle Siege share one schedule. Arca War runs on the same days on both realms at different hours, and Icewind Valley runs 8x a day on the Speed Realm Autumn Edition against 2x on the Permanent Realm.
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