I think I've figured out why the centurion appears to be unkillable. It has everything to do with MWO's damage transference mechanic.
You see, the Centurion has huge arms which completely envelops the side torso, and huge side torsos which completely envelop the centre torso.
We have known for some time that Centurions appear to be nigh-unkillable after their arms have been blown off. I think I've found the reason.
Now, in Mechwarrior Online, there are two types of damage allocation. One is when you blow off a side torso, and the arm immediately has its health reduced to zero and blows off as well. The second is when you shoot a destroyed side torso... 50% of the damage will be transferred to the Centre Torso.
The fault here in the Centurion is that when the arm is blown off the hitbox of the arm is not blown off. It still exists, and it is still blocking the side torso hitbox. Now when you shoot the centurion from the side thinking to hit the side torso since it's arm is no longer there, the game still THINKS the arm is still there, so it transfers exactly half the damage to the side torso.
BUT! The side torso 50% transference mechanic still exists! Therefore, when you shoot the mech from the side again, this damage is halved, and halved again, and now your weapons will do exactly 1/4 of the damage they should. That is why it takes forever to kill a centurion!
The tests
To blow a side torso (zero internal health) from full health from the front - 12 shots with a medium laser. To blow a side torso from full health from the side - 21 shots with a medium laser. To blow the centre torso from full health from the side after blowing off the side torso: 56 shots with a medium laser.
So in other words, if you were to shoot a centurion from exactly one side, it would take... about 100 shots with a medium laser to kill it from full health. That's 500 damage.Well, actually slightly more than that, because Testing Grounds mechs have deficient armor.
P.S. Font sizes changed to reflect relative values so as to reflect the absurdity. For your reference, 500 damage is sufficient to CT-core 5 Heavy mechs from full health.
Current interim solution
Until a fix is implemented, shoot between the centurion's legs. That area counts as Centre Torso no matter how they turn their upper body.
Other applications
Stalkers have effectively double the CT armour if shot from the side after the Side Torso is blown off. And since the Stalker has a very long... erm... centre torso, most of the time you're facing its side. So when you shoot it, most of the time you're actually dealing only half the damage you should. That's why Stalkers appear to live longer than Atlases - because Atlases have a very easy-to-hit Centre Torso from even the side, whereas the only way to hit a stalker's CT is usually if it's aiming directly at you... not a good situation for you. Again, shoot between the Stalker's legs to fix this.
This was also the reason why Ravens used to be impossible to kill, and now are very hard to kill on the torso. The arm is shielding the side torso - which means that shooting the side torso as it passes with its side facing you always dealt 1/2 expected damage. This makes the Raven seem like it's very easy to leg in comparison why is why many players have always been legging it... but it was never the case that the legs were weak, but it was that the rest of the Raven was too strong.
Light mechs in general present you with the side profile nearly all the time, unless they're shooting you. I didn't test all the light mechs by shooting them from the side, I'm sure someone might want to, but the thing is that if its arm hitbox wasn't eliminated, shooting them from the side would always do 1/2 health.
Perhaps those players 4 months ago who remarked that it seemed like light mechs have doubled armor were actually completely right.
This whole ST shielding nonsense isn't a factor when we consider slow mechs who turn slowly since you have a lot of time to shoot them. Whereas any mech that can turn fast can in that turning motion instantly reduce any damage you deal to a fraction of what it should have been... which makes all fast mechs necessarily overpowered.
And lastly, this is why if you shoot the leg of a mech after you already destroy the leg, you will take forever to kill it. The damage is first transferred to the side torso at 50% rate, then transferred to the centre torso at 25% rate, if you keep shooting the destroyed leg. Whereas if you shoot the other leg it will blow in seconds.
Recommended fix
Not-so-preferred:
Completely remove the arm hitbox the moment the arm is blown off. Other mechs like Dragons and Catapults don't have this 'eternal arm' issue. Also, change the system such that shooting a destroyed leg will transfer damage to the other leg, rather than to the side torso it's attached to as per the MW4 system.
OR
Preferred:
Remove this 50% allocation mechanism from the game completely, and allocate full damage to the next component once one component is destroyed.
Until this damage allocation problem is fixed, the chassis will never be balanced correctly because the same weapons don't do the same damage on different targets. This has made the Centurion completely broken ever since its inception, and we can fix it now.
Once all of the mechs finally have this annoying damage allocation bug fixed, we'll no longer see absurd situations like JR7-F dueling an Atlas head-on and winning with >50% health to spare.
Thank you.
Edited by Hayashi, 26 May 2013 - 07:40 AM.