Turn rate is the speed at which a unit can turn. When moving to a location, a unit first turns to face that location, then begins walking. Similarly, when targeting another unit with an attack or spell, a unit first turns until it is facing the target, and then continues with the action. A unit only starts moving, or only starts casting a spell on a targeted area or point when the target is within 11.5° angle in front of the ordered unit. This can make kiting more difficult, as the hero has to spend time turning towards and away from the target with each attack.
Every unit has a base turn rate, which can be lowered by some abilities. The vast majority of heroes have a turn rate between 0.4 and 0.6, meaning it takes between 0.15 and 0.23 seconds for the hero to make a 180 degree turn.
Turn rate is expressed in radians per 0.03 seconds. A 180 degrees turn is the same as π (3.14) radians.
0.03π divided by the turn rate of the unit equals the time it takes to turn 180 degrees. A turn rate slow is directly applied to the base turn rate. For example, a turn rate slow of 70% on a unit's 0.5 base turn rate lowers the unit's actual turn rate to [0.5 × (1 - 0.7)] = 0.15.
(0.03π / T = t, where T = turn rate and t = the time it takes to turn around).
- A hero with a turn rate of 0.6 takes roughly 0.157 seconds to turn 180 degrees. (0.03π / 0.6)
- A hero with a turn rate of 0.4 and a turn rate slow of 70% takes roughly 0.785 seconds to turn 180 degrees. (0.03π / (0.4 × 0.3))
- A hero with a turn rate of 1.0 and a turn rate slow of 70% takes roughly 0.314 seconds to turn 180 degrees. (0.03π / (1.0 × 0.3))
- A hero with a turn rate of 0.4 and turn rate slows of 70% and 50% takes roughly 1.571 seconds to turn 180 degrees. (0.03π / (0.4 × 0.15))
However, a unit does not immediately start turning at the highest rate it can turn. The turn rate ramps as the unit starts turning, reaching the unit's max turn rate after a certain amount of time. The rate at which the turn rate ramps up is unknown.
If a unit starts turning due to an ability or item cast order (by targeting a point, area or unit which is not within the required 11.5° facing angle), the turning cannot be canceled by a move, attack or a new spell cast order. Any command ordered while turning due to a spell cast order gets queued up and executed once the spell is cast. In order to cancel the spell or ability cast, the player must issue a stop or halt command, in the same way how to cancel spell during its cast animation. This is to prevent accidental canceling of casts due to fast clicking. Issuing a stop or halt command does not stop the unit from turning if it has already started to turn, but stops the order which initiated the turning. This allows for example Templar Assassin to turn during Meld without canceling the ability, as long as the move command is stopped before the targeted point is within the required angle.
Turn rate comparison
Below is a comparison of the turn rates of all heroes.
- Io: Despite not requiring to turn in order to take any action, Io still uses a turn rate (0.7). This means, despite starting to move/attack/cast spells instantly at a target behind it, Io still requires roughly 0.13 seconds to turn 180° and face towards the target. This still existing turn rate affects spells which work with the facing angle of the targeted unit, like Blink Strike, Cloak and Dagger and Force Staff. In order to distinguish where Io is facing its front is marked visually by an arc.
- During Omnislash, Sleight of Fist, Icarus Dive and Sun Ray, the caster does not require to turn to take actions either.
- Torrent, Shadow Amulet, Glimmer Cape, Bottle, Clarity, Enchanted Mango and Healing Salve do not require their caster to face towards their target.
Abilities affecting turn rate
- Increased the speed at which turn rates of units ramp up by 15%.
- Cast behavior while turning to cast has been adjusted:
- Previously if you cast a spell and were already in range, but not facing the target (outside of the small cast angle), your hero would start turning, but not consider that turn as anything beyond normal movement from an order priority perspective. This meant that issuing any order while turning, during that very short threshold window, would not be in the order queue in the same way as once your casting time started.
- It now treats your order as the same once you are in cast range.
- The effective difference this has is that you can queue your actions in the same way after you click one ability without depending on the angle of cast being 16 degrees or 20 degrees. Previously if you issued the order at the wrong degree, it would completely interrupt the ability, rather than queuing it to do after your existing order finished as is the usual spell casting behavior.
- This subtle difference applies most commonly with Blink Dagger, as you could easily accidentally cancel your blink order if you clicked the other ability before you reached the critical angle (since otherwise Blink has 0 cast time).
- Riki's Smoke Screen now reduces turn rate by 30%.