Many high-level Barbarians choose Whirlwind as their main skill.
To best use Whirlwind, lead a group of monsters into a tight pack, then click past to the other side of the monsters. The Barbarian will fly through them damaging and destroying them very quickly.
Long Weapons such as Spears, and Polearms make Whirlwind even more effective as it will hit monsters in a wider radius.
Whirlwind consumes a lot of mana and puts you in close contact with monsters, so mana and life-stealing weapons or items are necessary to use Whirlwind constantly, especially in Nightmare and Hell difficulties.
You cannot use potions or any inventory items while using Whirlwind.
Whirlwind does not work with: "On Attack", "On Striking", or "When You Kill an Enemy" item properties.
Whirlwind is affected by weapon speed as follows. After you click to start your Whirlwind attack, the game checks for a hit on a target in range at the 4th and 8th animation frames (recall that the game runs at 25 frames per second). After the first two "free" hit-checks, the frames elapsed in-between subsequent hit-checks will depend on your weapon speed. Note: increased attack speed from items outside your weapon does not affect Whirlwind - only the speed of the weapon itself counts. The dependence on weapon speed is obtained by subtracting your weapon's increased attack speed (IAS) to its base weapon speed and checking where the number you obtain fits in the following table:
- One-handed weapons
Breakpoints: 15, 10, -10, -34.
Number of frames in-between hit-checks after frame 8: 12, 10, 8, 6, 4
- Two-handed weapons
Breakpoints: 15, 0, -10, -30, -60.
Number of frames in-between hit-checks after frame 8: 14, 12, 10, 8, 6, 4
#1 War Pike of quickness (two-handed weapon)
Base weapon speed: 20
Weapon increased attack speed: 40
Whirlwind speed: 20 - 40 = -20
Breakpoint reached: -10
Number of frames in-between checks: 8
Hit-checks at frames 4, 8, 16, 24, 32, etc.
#2 Falchion (one-handed weapon)
Base weapon speed: 20
Weapon increased attack speed: 0
Whirlwind speed: 20 - 0 = 20
Breakpoint reached: none
Number of frames in-between checks: 12
Hit-checks at frames: 4, 8, 20, 32, 44, etc.
#3 The Grandfather Colossus Blade with ' Shael' (one-handed weapon)
Base weapon speed: 5
Weapon increased attack speed: 20
Whirlwind speed: 5 - 20 = -15
Breakpoint reached: -10
Number of frames in-between checks: 6
Hit-checks at frames: 4, 8, 14, 20, 26, etc.
Note: two-handed swords are treated as one-handed weapons for Whirlwind purposes, regardless of the sword being held in one-handed or two-handed mode. The above calculation for The Grandfather, therefore, holds for any way the sword is held.
Barbarians wielding weapons with slow Whirlwind speeds should try and keep their whirls very short, so as to take full advantage of the 4th and 8th frame "free" hits. Hold down the Whirlwind button and hover the cursor just right after the place where the Whirlwind starts. The free hits are taken and almost immediately after it, the Whirlwind stops. Then, since the Whirlwind button is still being pressed, a new Whirlwind starts and we get back the free hits of frames 4 and 8. Keep doing this in a triangular pattern. By using this technique you minimize the time under which your weapon slows down whirlwinds. This tactic is used by many Barbarians online and is nicknamed "The Dance of Death". This is because you keep spinning close to the target, not zig-zagging in long lines back-and-forth.
When dual-wielding, both weapons try to score a hit against the target. In other words, the game does a hit-check for each weapon. Since both weapons are given the chance to score a hit, the damage done over time is roughly the sum of the damage of both weapons, which is comparable to the damage done whirling with a two-handed weapon. The effect of weapon speed in dual-wielding Whirlwind is as follows. While a target is in range, one of the weapons' speed is constantly used to calculate the next hit-check frame. If there's no target in range, the game will alternate between weapon speeds to calculate the next hit-check frame. The best way to make sure you have maximum Whirlwind speed when dual-wielding is to use weapons that both reach the final breakpoint, like for instance a Lightsabre Phase Blade and a Colossus Blade with 40% IAS.
Whirlwind will not stop until you reached your destination (ground or a monster). If you clicked on a monster that flees, Whirlwind will not stop until you reached the monster, or the path becomes blocked by obstacles. It is possible to become stuck in Whirlwind over many screens. This is an issue, especially in hell difficulty, because it can lead you to unexplored areas with monsters. So try clicking on the ground but not on the monsters. Again, Whirlwind will not stop even on occasions that normally stop you. Stun attacks will have no effect, and knockback will not knock you back, even if your weapon breaks, it will be broken after Whirlwind ends. Whirlwind will not stop even if you take damage enough to kill you. You will die after the Whirlwind state ends. So it is possible to avoid Death by a quick save and exit.