HighFleet Sudden Strike Explained


Many people don’t understand why there is a “chance” for sudden strike and how the odds are calculated. This guide will give you all you need to know about it.

The Yellow Bar

HighFleet Sudden Strike Explained

When you are in visual range of a garrison, you can see its shiny yellow bar flashing over its head, and is ticking its way down.

This bar indicates how long before they know what’s going on and becomes combat ready.

The bar length is randomized between 15~45 minutes and you have no way to know prior to it starts ticking, hence the “chance” of your successful sudden strike.

Note that garrisons usually don’t have radar, so you may assume visual range. The chance listed in shipwork design is assuming fleet parking in town having the corresponding sensor. The radar range is reduced to 400 km when landed; IRST range is unaffected.
The red ring of the town indicates the landed ships’ radar range (outer boundary) and IRST range (inner boundary).


When you are discovered by a combat ready enemy, they will send out an alarm and it’ll show a timer on your clock indicating “Sudden Strike Impossible”. It’s more complicated than that.

When the alarm is raised, all active garrison starts ticking down their own yellow bars. If you already have a force close enough to the enemy, you may be able to reach it before the yellow bar runs out, thus still achieving sudden strike.

After the alarm is over, there will be approximately 2 hours of time for their yellow bar to reset. During this time, if you attack, they will still be considered on alert and they will be airborne while being able to report your location immediately.

Prize Ships

They have an approximately 5~10 minutes timer and are considered on alert when departing a city, which over a certain amount of time (4~6 hours) may reset and become ambush-able.
You can use Fire Control Radar to see if they have yellow bar over their head. If not, it means they’re on alert at that moment and may instantly report you and raise alarm.

(Not verified if normal mode spawn these)
On hard mode only, prize ship may have escort ships that are equipped with a 500km range radar.
It turns out that trade convoy doesn’t care about radar contact.


If you want a totally stealth playthrough, Fire Control Radar and ELINT is mandatory to not accidentally run into an on-alert trade convoy. Otherwise, make sure you can bridge the visual distance (75km at midnight, 100km at noon) within 15 minutes to guarantee sudden strike on garrisons.

We would like to thank CodeNemesis. He is the one behind this wonderful guide.