Invisibility detection in Dota 2: Sentry, Dust and Gem
Invisibility in Dota 2 is broken by True Sight. It's granted by three items — Sentry Ward, Dust of Appearance and Gem of True Sight — and each serves its own job. We break down how they differ, why a regular Observer can't see invisible heroes and how to detect properly. No patch ties — just principles.
What True Sight is
An invisible hero can't be seen with ordinary vision — only True Sight reveals them. It's a special type of vision granted by just a few sources: the items Sentry Ward, Dust of Appearance and Gem of True Sight, plus a handful of hero abilities. Without True Sight you can neither see an invisible hero nor target them.
A regular Observer gives vision but does NOT detect invisibility. True Sight comes from Sentry (a spot), Dust (the chase) and Gem (permanent). Cheap detection is a mandatory part of your buy against invisible heroes: one well-timed Sentry pays for itself with a whole saved fight.
Sentry Ward
Sentry Ward is the cheapest detection, around 50 gold. It's a stationary ward: you place it on the terrain and it grants True Sight in a radius around itself for as long as it stands. A Sentry lasts a few minutes but gives no terrain vision — it only reveals what's invisible.
- Spot control. Sentries go on rune spots, chokes and the approaches to Roshan so the enemy can't walk in invisible.
- Deny enemy wards. A Sentry reveals enemy Observers — it's the main dewarding tool.
- Paired with an Observer. The Observer gives vision, a Sentry beside it gives detection. Together they cover both "I see" and "I see the invisible".
How to place wards for vision and detection is covered in the warding in Dota 2 guide.
Dust of Appearance
Dust of Appearance is a consumable for roughly 80 gold. Unlike a Sentry, it's used on your hero and for a few seconds reveals every moving invisible target nearby — and also slows them. It's a tool for the chase and the fight, not for spot control.
- Catch the runner. Dust reveals and slows an invisible hero trying to escape into stealth.
- Carried in the inventory. A charge or two of Dust on a support or core against an invisible enemy almost always pays off.
- Doesn't beat every effect. Some abilities clear Dust or hide from it — so the Dust + Sentry combo is kept together.
Gem of True Sight
Gem of True Sight is the most expensive and powerful detection, around 900 gold. While it's in the inventory, the carrier permanently has True Sight around them — no consumables, no timers. But the Gem comes with a risk:
- Drops on death. If the Gem carrier dies, the Gem falls to the ground — and the enemy can pick it up.
- Carried by the safest player. Usually the Gem is held by a hero deep in the formation who doesn't dive first.
- Hidden before a risky fight. The Gem can be stashed in base or hidden so you don't gift it to the enemy.
How a support finds the gold for a Gem is covered in the GPM and XPM guide.
How and when to detect
Detection isn't "buy it and forget" — it's the habit of reading the game:
- React to the pick. If the enemy has an invisible hero, detection in your buy is mandatory from the early minutes.
- Sentries on key spots. Runes, the approaches to Roshan, narrow chokes: that's where an invisible hero is most dangerous.
- Dust for the fight and the chase. Carry a charge to catch up or to deny the escape into stealth.
- Gem when you need permanent detection. Against several invisible heroes one Gem is cheaper than endless consumables.
FAQ
How do you detect invisibility in Dota 2?
True Sight is granted by three items: Sentry Ward (a stationary ward with a True Sight radius), Dust of Appearance (a consumable that reveals and slows moving invisible targets around the hero) and Gem of True Sight (permanent True Sight around the carrier). A regular Observer does NOT grant True Sight.
Can an Observer Ward see invisible heroes?
No. An Observer Ward only provides vision of the terrain and does not reveal invisible heroes — for that you need a Sentry, Dust or Gem. That's why an Observer and a Sentry are placed together: one gives vision, the other True Sight.
How does a Sentry differ from Dust?
A Sentry Ward costs around 50 gold, is placed on the terrain and grants True Sight in a radius for as long as it stands. Dust of Appearance costs around 80 gold, is used on your hero, reveals moving invisible targets nearby for a few seconds and slows them. Sentry is for holding a spot, Dust is for the chase.
What happens to the Gem when its carrier dies?
Gem of True Sight drops from the inventory on death, and the enemy can pick it up. That's why the expensive Gem (around 900 gold) is carried by whoever is least likely to die, and it's hidden or returned to base before a dangerous fight.
Map control is a habit you can learn
Placing a Sentry in time and denying the enemy an invisible entry takes hundreds of games to master. While the skill develops, a boost helps you break through the ceiling. Not sure which format fits — message us in the chat.