2d6 Deadly Mech Failures

The Ballad of JJ Bangaroo
The flames erupting from the steel carcass over the dune. While the green blood from the giant was spilling on the dune in a fountain of fire, the red blood from the gunslinger was staining the sands of the outbacks.
"4 holes, punctured lung, pulverized femur. Looks like you're a goner this time, JJ."
Gurgles of pain, covered by the words of the flaming thunder, as the Doc's hairy paws checked underneath the bloody clothes.
The battle was over. The merchant's Bull was gone, but it's cargo container was not. The Bangaroos' stayed undefeated. Their spirits were not.
"We can't just let him die like that Doc! You gotta do something!"
JJ's gun was there. One bullet left. Fate's last laugh, in the face of burning hellfire and the bloodiest victory to date, underneath the shadow of the Flying Englishman's bovine head.
"I can't do shit. JJ gotta decide how he's gonna go. There you are sonny. What shall we tell her?"
The gun was cocked and put in JJ's bloody hand. A deep breath, a last gurgle before the flash.
"Kill... that fuckin' hoe..."

PEW PEW PEW
Random Lego Mechas from the Internet.

What's This Bullshit, Anyway?
This was made for a campaign (actually a test drive for a whole new game) which was started and enjoyed for about 6 sessions if I recall correctly.
The campaign/game was called Raging Bulls. Set in an alternative 1890, where England never lost colonies due to giant mechas and super bio-fuels (yep, the mechas had bovine heads and I think you all can easily guess how they were called). So, basically, America is a giant farm for PowerGreen (the fuel) and an industrialized colony choke-full of mutants, Europe except for England has gone to shit due to an ecological disaster and became a toxic jungle, African colonies became full of refugees from Europe trying (and partially succeeding) at rebuilding their nations there, Asia was under Chinese hegemony and nobody knows what the fuck is happening there, and Australia is a toxic deforested desert ruled by convicts and mostly abandoned by both God and the Queen (but this could change pretty fast).
So, it was today's world with bovine-headed mechas called Raging Bulls, because they are fuckin' rad and we wanted to be that rad without doing meth (yeah, we're posers).

Mooooooo.
Raging Bulls Concept Art by Luca Coppola.

That Didn't Explain Shit!
Ok, ruley stuff: Raging Bulls were like small characters, so they had their own sheets with stats, equip and so on. Most of that is totally useless right now, so important stuff only:
-Size: bigger Bulls hosted more people, consumed more PowerGreen (aka were more costly to refill), and were sturdier;
-Speed: how fast the Bull goes with a Piloting Action (which took as many turns as the Size of the Bull, forcing people to plan ahead).
-Armor: extra Structural Integrity (which was HP and was kinda strange because we actually used an Ammo Dice for health of characters), and extra defense for people inside. It could easily be hacked together from scrap, so Bulls had like a sort of "buffer HP" that wasn't that costly to repair (which was extremely important, since they were Australian rednecks running around the desert like hungry Warboys and never had enough food for the whole week, so they never really had the resources to repair anything);
-Fuel: how much PowerGreen there was left (pretty interesting since it was pretty scarce, and anybody who could get a supply line of the stuff basically became a warlord on its own, since Australia had little to no industry and most of it was coming from outside or scavenged from abandoned English deposits and other less-than-savory resources), represented by an Ammo Dice with variable consumption rate (based on how much you wanted to get stuff done, so it was kinda risk-vs-reward but I'm not too sure it was a good idea overall).

MORE PEW PEW PEW.
Lego Mech designs for Mobile Frame Zero from the Internet.

The Actual Table

Whenever a Raging Bull reaches 0 Structural Integrity, roll 2d6 to see what happens with the broken machinery:
2-3: The Bull stops dead in it's track, the engine is broken but not beyond repair. Any excess damage goes to the occupants but can be negated with an Armor check.
4-5: The Bull's weapon get hit. Any ammo inside is broken and inflicts 1 point of damage to the occupants. Roll a d6 for each weapon, it's has 3-in-6 chances of being broken beyond repair.
6-7-8: The Bull's frame is bent and broken, with whole pieces of it coming down. Armor is immediately set to 0. For each extra damage, roll 1d6: there is a 4-in-6 chance that the Bull falls down, and any excess damage goes to the occupants.
9-10: The Bull's legs take the hit, unbalancing it and inflicting 1 damage to the occupants. The Bull permanently loses 1 point of Speed.
11-12: The Bull's engine is teared apart, releasing the toxic, flammable hell in its tank. Everyone inside dies, the Bull is destroyed and it erupts in a giant column of flames, which lasts 10 minutes per Fuel remaining.

This random table in a nutshell.
"Da Bulls" sketch from SNL.