This card is just aggressively bad. Let's start with the functionality, because that's where all the other choices on the card fail to accurate reflect.

Telescopic Sight requires a two-handed firearm. Now that seems okay at first, but then you remember that Marksmanship allows you to do this with any gun. And it provides an extra damage to boot. Now you may make the case that Marksmanship is only one use. But at best, Telescopic Sight is one use per turn. Yes, it exhausts for some reason.

You cannot make the snipe shot at Elite targets. Typically Elites are the scariest enemies, and the ones you're least likely to want to end your turn engaged with. So being able to plink away at them from range would be useful. Naturally, they have taken that away from the card. Please note that Marksmanship does not have this problem.

You cannot shoot an enemy in your face. That's really bad when using a two-handed weapon, as it means you now need a Bandolier so you can carry a second weapon or an alternative means of removing an enemy from your face to be able to continue using your weapon. Please note again, Marksmanship does not have this problem. This is the entire reason Springfield M1903 is bad.

You also cannot shoot into a connecting location if an enemy is in your face period, even if they are not the target of the attack. As someone with a gun, this is often going to be a thing that happens when trying to kill enemies. Marksmanship still doesn't have this problem.

Finally as a card it has the no Will sampler platter of icons which isn't exactly where a Guardian wants to be. Cards without doubled icons are a hard sell for me, unless you're always intending to play them for their primary function. This one doesn't have a good primary function, so it should at least make up for the 3 XP cost with good icons (which it doesn't).

So I keep bringing up Marksmanship which in itself isn't exactly regarded as a stellar card. It's cheaper for a single use than the scope, does more damage than the scope, and requires less XP than the scope. And did I mention you can put it on Stick to the Plan? Two scopes is 6 XP, but Marksmanship plus Stick to the Plan is only 7 XP for the ability to guarantee you'll see the card. Still doesn't require a two-handed weapon either, it's going to work on your .45 Automatic (2) if you're a mad lad.

Tommy Muldoon straps on his Flamethrower. Then he bolts on the Telescopic Sight.

As he is engaged with no enemies, Tommy uses the replacement targeting restriction to take aim at an enemy at an adjacent location. He commits a card. During the player window before success is determined, he taunts a different enemy two locations away. That enemy runs in to engage and Tommy tries to kick it in the face. The kick misses, but the enemy trips. The attack on the first enemy is successful and deals no damage; instead the flames from the thrower incinerate the second, now engaged enemy. The original enemy is stunned by the stupidity of it all.

With the latest taboo (summer 2021), telescopic sight goes from an extremely situational card that you have to build around… To a situational card you have to build around. It's still a 3xp card you can’t use on others, and it can only trigger off a half dozen cards in guardian, and many of those start at three XP. (You can use it on Becky, the Thompson or the Winchester, but those are slim pickings.)

At its best, this is marksman on tap. Campaigns like Dunwich love spawning aloof enemies and putting them nearby, or regular enemies ahead of you. Same thing with the Innsmouth Conspiracy, although a hiding space or two will make this much more viable. (Oddly, you can use your telescopic scope while driving at 50 mph.)

But it’s a puzzle piece, and if you bring this, you’ll probably want extra ammo, enchant weapon for more damage, blessed ammunition, and well-maintained. And without two or three other players, you simply won’t have the enemy density to make this worthwhile compared to get over here or the riot whistle. Pair with Trish, Rita or Winnie for easier targets and less misfiring.

In case if you're wondering "Which firearms this can be used with?" — here's a link to handy list.

It's funny to think about Jenny's Twins or Joe's colts with a telescopic sight...

UPD 06/28/2021: WOW! New Taboo is a game changer, they've dropped "Attached asset cannot be used to attack enemies engaged with you." part, so we can attach this to a Lightning Gun and go bananas!