I tamed one today with this strategy! You only need some stone pillars and that’s all!
So firstly I placed the pillars in a line with a little gap just so I could shoot through. Then I placed more pillars so it made a box with one side open like a U shape .
Secondly I hit the Rex once and it aggroed on me while I ran and trapped the Rex into my cage. It didn’t turn around but instead tried to break the cage (So I didn’t close the cage) . Then I shot normal arrows onto it because I didn’t have any tranq.
After a while it should turn around and run away. I followed it and wacked it with my bat for around 15 seconds and it became unconscious.
Finally I tamed it in around 15 minutes with only 10 dizzying potion (I forgot what it’s called but it’s the one which heals you and makes you unconscious)
And that’s how you take a Rex with a very low level! You don’t even need tranq arrows! I hope this works for you I took 8 minutes writing this so I will appreciate the upvote!
If you use the bear trap strategy which is if you lead it into a Dino gateway that is shaped in a triangle and with a bear trap in the middle (Large Beartrap) and when it is stuck you must put a dinogate behind it to trap it and then knock out. (hope this helped and "If" I win could it be an Xbox voucher, thanks.)
You can use the normal darts or arrows. But the fastest way to tame a Rex .
Get under its belly as fast as you can and rub its belly, instant tame :) all you new player try it out and you'll be riding like a king like us vets !!
Create a 3x3 mobile taming pen 3 walls high on a raft with a Dino gateway on one side and ramps on the other. Use a flyer to lead it up the ramp into the pen then move it to a safe area to tame. I got 2 150s without a single issue.