FTL Faster Than Light – How to Prevent Enemies from Going Through Doors on Your Ship

Here are some weapon images that might help you get used to identifying enemy weaponry:

• The top row are bombs, from left to right, the small bomb, the ion bomb, and the breach bomb. The bomb launchers all look the same, and you'll only see the bomb itself for a very short time after it is loaded, so it's unlikely that you'll know more than "they have a bomb weapon" unless you're paying very close attention.
• The second row are beams - the bio beam and the halberd beam. Note the design is a 2-pronged fork. As they charge, the lights on them start to glow.
• The third row are laser weapons. The first is a burst laser mk. 3, then a single laser, and an ion weapon. The lights light up as they charge.
• Finally, the fourth row is missile launchers. The two I had easy access to are the same shape, so this wouldn't be super useful for identifying anything more than "it's a missile weapon."

Note that ion weapons glow a particular shade of blue - both the bomb and ion "laser" weapons glow the same color.

In the final sector, you'll come across:

a "final boss" of sorts - the rebel flagship. The weapons follow the same general design, but are slightly different in appearance. It's weapons are, from left to right, an multi-shot ion cannon, a multi-shot laser, a 3-shot missile launcher, and a beam weapon.

I can't inline this one and keep the spoiler space, but here's an image of its weapons.

The outermost two weapons are damaged in your first encounter, but the other two persist through to the end. It's final form has a massive burst-firing energy weapon that has no corresponding visible firing point or related subsystem.

There is an augmentation "Weapon Pre-Igniter" that powers your weapons instantly when you come out of the jump. But even with this it is very hard to stop the teleporter. You need to either have sufficient firepower to bring down the shield and teleport station in one go. Or have enough shield bypassing or enough EMP firepower to be able to bring down the teleport station.

You also need to keep it down the whole battle, if it is repaired for a short time it will probably instantly teleport boarders on board. (This I think, I have not tested this).

When I had a ship with the Weapon Pre-Igniter, I never was able to stop the teleporter quick enough to prevent boarding from taking place. I have not tested this very extensively btw.

Taking out the teleport pad does prevent them from returning to their own ship, a blessing and a curse. (They do not teleport away before you can get the EXP. But on the other hand, you still have boarders on your ship)

The enemy can't teleport to a cloaked ship or retreat their troops from a cloaked ship. So you can use Stealth Weapons augmentation and cloaking to blast away the teleport pads of the enemy ship.

And, the Zoltan Shield also prevents ships from teleporting boarders on board. (Events still work).