So I just knocked a Rex out and I am taking him right now but I suggest getting on a fast raptor or something fast to run away from it and every now and then just look back and tranq it. That is a good way but I was just standing on a big rock, although it is hard to find a good rock and my backup plan was to mount my argy and fly far enough to where I could get a few shots on him before I had to retreat again because this one was slow. Hope this helped and don’t mind about pressing the like, I am just glad to help. :)

If your looking to tame one of these I found a simple hack that allows you to get prime to tame it without going and killing things which takes a long time. Breed a baby dodo and kill it, when you do it will drop prime meat and that’s an easy way to get it.( hope this tip helped

So basically of you don't want to encounter these, you can just like go base in a cave they never spawn there same with a lot of other dangerous creatures in The start of a playtrought like gigas, dodos, reaper Kings and argentavises so yeah so that is My tip for avoiding rexs it works 100% of The time

Without doing the usual thing of telling a massive story, I'll only say this. I almost tamed a lvl 145 Rex, but I made some mistakes.

I only took as many narco arrows as I needed, when I should of brought 3 times as many, for the shots I missed, and the times when I had to run away and come back, giving it's torpor time to wear start going down.

I should of left at the crack of dawn, or sooner. I fought it for so long, I was still fighting it at midnight.

I should of brought a backup Crossbow, or 2. When my crossbow broke, I had to sprint back home to repair it, which cost me valuable time, torpor, and lead to my final mistake.

I should of kept a better track of where any nearby alphas or other Rex were. I almost lost it when it ran in the direction of an alpha Raptor and it's pack, but managed to kite it away, and later in the evening, either by luck or instinct, it fled to the safety of a nearby 150 alpha Rex.

I eventually had to give up after using 60 more arrows than I should of needed, needing to replace my crossbow, chasing it around till midnight, (at which point I was having to switch between the torch and crossbow to shoot blind) and chasing it towards an Alpha Rex.

Next time, I'm leaving before dawn, bringing 3 crossbows, 300+ narco arrows, and maybe killing the alpha Rex and alpha Raptor first (though honestly, I'm scared to try, and lose my best dinos. Why did there have to be a level 150 alpha Rex so close to my starting zone base?! And a level 145 Rex not too far away from it, teasing me with the chance to have an OP Rex so early into the game)

I was once looking for any thing new i could tame, then i saw an a dino running so i took a look and found a rex following it, it was a lv 2 rex that i tamed with almost 15-20 shot with a crossbow. The rex is very strong and would probably kill me 1 shot but was too busy killing the dino

Step 1. Get 2 takes wth over 2,000 hp just to be safe

Step 2. Put the tames on passive but have them follow u

Step 3. Have the tames tank the hits while u start tranqing

Step 4. Wait until the rexs torpor is less than 100 then put food in it u shouldn’t need any narcotics but take some just in case