Detect and Ranged Attacks

[Refplace]

Originally Posted by Engurrand

I have seen this interpretation expressed on these forums. I'm going to call it the Refplace Interpretation.

Under this interpretation, you would be using Detect to 'spot' the enemy by their [whatever you Detect] characteristic--in the case of Telescan, it would be their mind. Once you've spotted them you could then shoot them, since you know where they are. If they move, you might lose sight of them and have to require, but only if you weren't paying attention. Detect is not subject to darkness or cover penalties, so there should be no reason you would suffer those penalties once you'd successfully spotted an opponent.

It seems like it is a valid interpretation of the text in Basic, and I know players who argue for it strenuously. But the text of Telescan in Psionic Powers, as well as the rest of Detect-derived powers in PP, state or at least strongly imply a very different and incompatible interpretation: Detect is not a passive sense at all, but only occurs with concentrate maneuvers that _momentarily_ reveal the direction (or with Precise, the direction and distance) to the target. This I'm going to call the Anaraxes Interpretation. Under the Anaraxes Interpretation,

For Telescan specifically you get Lock-On at the start and can use telepathic abilities to attack but not other abilities. This is because it has Vague at level 1 and does not get Precise until level 4.
Vague does not give you direction or distance, only the presence of what your detecting. That does not matter with telepathic abilities which are typically and often explicitly called out as not caring about that. They work regardless of distance through mindlink for example.

You are correct in that base Detect is not a passive ability and so a momentary glimpse. However earlier questions were do you need Reflexive, to turn it into a useful targeting ability and IMO the correct answer was given which is no.
Base Detect requires that pesky Concentrate maneuver, however you can get around that by one of the following.

• Compartmentalized Mind or Altered Time Rate - granting you an extra maneuver so you can target then shoot in the same turn.
• Reduced Time, +20% (p. B108) or Reflexive, +40% (Powers, p. 109) which effectively includes a level of Reduced Time. Either means its a Free Action to use Detect, allowing you to sense then immediately shoot.
• Attacking a stationary target.

You'll need Precise, +100% in all cases to make a typical physical attack though. Precise is required to learn the distance and Targeting makes that more exact by effectively adding as a rangefinder. Not that +3 bonus on Aimed attacks is similar to using rangefinders from High Tech or Tactical Shooting.
GURPS Powers: Enhanced Senses by Bill (WHSWHS) explains some of this better than Basic since its a focused supplement.
For supporting evidence I looked at Enhanced Senses and found a Detect without Reflexive specifically available for targeting in Proximity Sense (p. 18) that does not have Reflexive. Though I do think it should have Reduced Time as described and is an error.
Most Detects in that book are built with Reflexive so they work all the time, even possibly waking you up if needed.