Question · Placement · Signal · Inference · Action
Dota 2 Scan guide: ask what the result can actually answer
Scan is not temporary omniscience. Give one shared team signal a bounded question, cover the route or area that matters, read positive and negative results narrowly, and choose a response that survives uncertainty.
Product boundary: DotaSense does not read Scan availability, detect its use, choose the area, see the result, identify heroes, track movement, read vision, inspect Roshan, or decide the response.
Reviewed August 28, 2026. Scan cooldown, start state, area, duration, eligible targets, result presentation, visibility, Roshan interaction, alternate modes, and UI can change. Verify the live minimap control, tooltip, targeting preview, result cue, team message, Demo Hero where useful, and Valve’s current Dota 2 updates.
How does Scan work in Dota 2?
Scan is a team information control on the minimap. You target an area, the live interface samples for eligible enemy presence, and the team receives a result cue. The useful answer is narrow: did the current Scan signal presence in this tested area during its active window?
It is not normal vision or True Sight. It does not justify an exact hero identity, count, formation, destination, spell state, ward location, mine field, or guaranteed route. Read the current UI for availability, cooldown, targeting, active duration, and signal behavior; those mechanics have changed since Scan was introduced.
The question-to-action Scan model
A technically positive signal can still be useless when nobody can act, and a negative signal can be dangerous when the team silently upgrades it to “the whole side is safe.” Begin with the decision. If either result leaves the same action, preserve the shared resource and use current vision, waves, hero positions, or patience instead.
Scan rule: the result updates one map question; it does not solve the map.
The five-step Scan decision test
- 1Verify the live control.
Read availability, cooldown, target preview, patch, mode, current vision, team positions, and whether another player is already communicating a use.
- 2Ask one question.
Name the area, time, eligible presence, and decision: “Are eligible enemy heroes crossing this approach before our wave reaches the tower?”
- 3Place for consequence.
Cover the route or hold point that matters when it matters, not the most visually suspicious center. Include movement during the active window and nearby bypasses.
- 4Read only the signal.
Separate positive, negative, late, displaced, and ambiguous results from stories about identity, count, destination, safety, or the objective itself.
- 5Name action and cancel.
Ping the result, choose move, hold, split, ward, retreat, or decline, then state what new evidence cancels that response before the signal becomes stale.
Ask a bounded question before spending the shared Scan
Where must presence matter?
Name a specific approach, pit, high-ground pocket, lane cut, camp corridor, retreat line, gate exit, tower flank, or farming boundary. “Their jungle” is usually too broad to place or interpret well.
When must the signal occur?
Tie the test to wave contact, objective damage, an ally’s travel, a missing hero’s plausible movement, a smoke call, a retreat, or the last moment your team can change formation.
What is Scan eligible to answer?
Use the live tooltip and cue. Do not silently expand hero-presence information into wards, mines, summons, exact identities, precise locations, item states, or abilities.
What changes on yes or no?
Write both branches before casting: positive means back, hold, split, ward, or turn; negative means advance one boundary, finish one action, save the spell, or collect one safer resource.
Place the search area for movement, not a screenshot
Cover a forced path
Bridge a choke, ramp, gate exit, objective approach, lane-to-jungle connection, or retreat corridor that the suspected heroes must cross. A route test often answers more than centering an old last-seen marker.
Price the boundary
A negative result says nothing about a hero just outside the tested edge. Check parallel ramps, trees, teleports, gates, mobility, vision breaks, high ground, and how quickly an adjacent position can become relevant.
Lead plausible movement
Last seen position is historical. Estimate direction, speed, pauses for farm or wards, objective timing, and the moment the result would arrive. Test the path the hero can occupy, not the pixel already abandoned.
Protect the response
Place where the team can still use either branch. A perfect signal after the wave dies, the ally is caught, or the exit closes produces knowledge without leverage.
Read positive and negative Scan results without inventing certainty
Eligible presence crossed the tested area
Update the threat boundary. Do not infer how many heroes, which heroes, whether they are grouped, whether they will continue, or whether the original suspected objective is happening. Combine the signal with missing portraits, waves, spells, item reveals, wards, sounds, projectiles, summons, and travel time.
No eligible presence registered in that test
Reduce probability only inside the covered area and window. The enemy may be outside the edge, early, late, stationary elsewhere, teleporting, using a different approach, or represented by something the current Scan does not test. Advance one supported boundary rather than declaring the map safe.
The placement or timing did not test the real question
A result can arrive after movement left the area, cover only one of several routes, overlap irrelevant presence, or have no reachable follow-up. Mark the uncertainty instead of converting a weak test into a strong call.
Use Scan in a suspected Smoke move without claiming the gank route
- Start with evidence. Missing heroes, synchronized lane disappearance, unusual wave abandonment, dewarding, objective timing, courier information, ally exposure, and common access routes can justify a question. Absence alone is not proof of Smoke.
- Test the threatened connection. Cover the path between the enemy’s plausible origin and the ally, ward line, objective, or farm boundary that needs a decision. Avoid casting on a huge vague destination after the danger already arrived.
- Positive means protect the boundary. Back the exposed hero, group on useful ground, break the approach with safe information, split the opposite map, or decline the objective. It does not prove every missing hero is together.
- Negative means keep respecting bypasses. Hold wards, formation, saves, teleports, waves, and exits. Move only far enough that the tested route’s lower probability changes the next action.
Use Scan around Roshan as a presence test, not objective proof
Remove the obsolete pit rule
Scan launched with an exception for units inside the Roshan pit. Valve’s 7.20 notes explicitly removed that exception. Old pages that say Scan never works inside the pit are stale; use the current target preview and result.
Test the decision area
Depending on the question, cover the pit, a likely entrance, a support setup pocket, the enemy approach, or the route your team must cross. One center cannot answer every Roshan question at once.
Combine with objective evidence
A positive result does not prove Roshan is being attacked. A negative result does not guarantee an empty surrounding area. Add current Roshan state, visible heroes, missing heroes, wards, summons, lanes, sounds, spells, damage, travel, and pit exits.
Choose a reachable response
Contest only when arrival, formation, vision, spells, buyback state, second lives, and exits make contact playable. Otherwise trade lanes, towers, camps, vision, or position and preserve the next window.
Build the full attempt around the Roshan timer guide, then use Scan as one evidence source inside that decision.
Give Scan one map job beyond Smoke and Roshan
Test the corridor that turns one camp or wave from supportable to isolated, then move the farmer, bring allies, ward, or abandon the last resource.
Test a flank or holding pocket that would change formation before wave contact. Do not use a negative result as permission to ignore teleports, buybacks, saves, and untested angles.
Test where a defender must pass to reach the wave or structure, then decide whether the split pusher finishes, hides, teleports, joins, or exits.
Test the choke or destination that determines whether the team can disengage. A positive may require a different route; a negative still expires as enemies move.
Test a likely deward or invasion corridor only when the result changes who shows, which ward is defended, or whether the team concedes the information area.
When several plausible paths exist, use the result to remove or strengthen one branch, then keep the remaining branches visible in the call.
Communicate the Scan as question, result, action, and cancel
“Scanning the gate exit for heroes reaching bottom. Positive: back our carry. Negative: finish one wave, then leave.”
“Scan positive on the east approach. Unknown count and identity. Hold ramp; do not cross until our ward or hero confirms.”
“Scan negative on the pit entrance only. Other entrance and teleports untested. Ward forward; hit Roshan after the wave shows.”
“Stop the move if a teleport starts, our wave dies, another hero disappears, the result expires, or the response reaches us before the action finishes.”
Valve’s Summer Scrub notes added alt-click communication for Scan’s cooldown state and a ctrl-click message advising the team not to use it yet. Prefer the current built-in UI when it expresses availability accurately; add only the tactical question and branch the interface cannot know.
Manage the shared cooldown without turning a copied number into truth
Read the live control
Check whether Scan is ready, cooling down, restricted, or altered by the current mode or effect. Communicate through the UI before building a play around it.
Share the next question
No single role permanently owns Scan. The teammate with the clearest decision-changing question can propose the use while everyone preserves urgent counterevidence.
Compare the next likely need
A low-value curiosity can remove information from the next Roshan, defense, high-ground, Smoke, split push, retreat, or farming-boundary decision.
Start only what you observed
If you use an external reminder, start it from confirmed live use and label it as a review cue. The current game UI remains authoritative for actual readiness.
Use official Scan history to avoid copied formulas
Original area signal
Valve introduced the team minimap ability with a 900 AoE, eight-second sample, 4.5-minute shared cooldown, smoked-unit consideration, no count, hidden enemy notification, and a Roshan-pit exception. Those are launch notes, not an eternal tooltip.
7.03 · cooldownThe first copied number changed
Bladeform Legacy reduced Scan’s cooldown from 270 to 210 seconds, directly disproving pages that still present the launch cooldown as current.
7.20 · RoshanThe pit exception ended
Valve stated that Scan no longer ignored units in the Roshan pit, invalidating the recurring “entrances only” rule repeated by the old guide.
Summer Scrub · interfaceCooldown communication entered the UI
Alt-click could inform the team of Scan’s cooldown state, while ctrl-click could advise teammates not to use it yet. Prefer current interface evidence over manual arithmetic.
Current updatesRecheck the live implementation
Search Valve’s current notes and verify the minimap tooltip, target preview, result cue, cooldown message, patch, and game mode before publishing exact mechanics.
A focused Scan replay drill
- Pause before use. Record availability, current vision, missing heroes, waves, objective state, last seen evidence, team positions, and every plausible route.
- Write the question. State the tested area, active window, eligible target, positive branch, negative branch, and the decision deadline.
- Draw the boundary. Mark which important routes overlap the target and which approaches, teleports, gates, mobility tools, or holding areas remain outside.
- Grade the inference. List what the result actually supports, what teammates claimed, and which identity, count, route, objective, or safety assumptions were invented.
- Measure the response. Compare the chosen move with ally travel, enemy access, wave contact, objective finish, vision, formation, spells, and exit.
- Find the first correction. Change one variable next game: question, placement, timing, call, positive branch, negative branch, or cancel condition.
Did the Scan answer the decision you needed?
Copy a focused six-field review question, share the observed signal and the two actions you considered, then compare one adjustment with another player. No app install is required.
Dota 2 Scan FAQ
What does Scan tell you in Dota 2?
Scan is a shared team information tool used from the minimap. Treat its live result as a bounded presence signal for the tested area and window, not as normal vision, hero identity, an exact count, a route, or proof of an objective attempt.
How long is the Dota 2 Scan cooldown?
Read the current Scan control for the live cooldown. Valve introduced Scan with a 270-second team cooldown in 6.87 and reduced it to 210 seconds in 7.03, demonstrating why an old fixed number should not override the current client, patch, or mode.
Can Scan check heroes in the Roshan pit?
The launch version ignored units inside the Roshan pit, but Valve removed that exception in 7.20. The old advice to scan only the entrances is obsolete; verify the live targeting and result while still accounting for heroes outside the tested area.
Does Scan reveal invisible heroes, wards, or mines?
Do not treat Scan as True Sight or general unit vision. Valve introduced it as an indicator of whether eligible enemy heroes were in the area and explicitly said it did not show their number. Check the current live rules for eligibility instead of using Scan to claim an identity, ward, mine, or exact location.
Does a negative Scan mean the area is safe?
No. A negative result is limited to the area, active window, and eligible targets tested. Enemies can be beside the boundary, arrive afterward, use another route, teleport, or remain in an untested area, so combine the result with current vision, waves, positions, and travel time.
Does DotaSense detect Scan use or track its cooldown automatically?
No. DotaSense can provide an optional reminder the player starts, but it does not read Scan availability, detect its use, choose the area, see the result, identify heroes, track movement, read vision, inspect Roshan, or decide the response.