Game breaking bug

[Souplex]

In Assasin's Creed 2 there's a cutscene where you're pulled out of the Animus briefly.
If the game is turned off during the cutscene then when you reload you're stuck in a warehouse as Desmond with nothing to do, and no way out.

 

[-Dragmire-]

The only game breaking bugs I've had were just crashes.

New Vegas didn't like something outside the starting town and CTD whenever that element attempted to load.

Skyrim became unplayable after installing Visual Studio onto my computer which would generate C++ errors seemingly randomly.

Borderlands 2 bluescreens frequently and Presequel bluescreens less frequently but enough to stop me playing.

Terraria Bluescreened (as of a previous version) if I had it set as fullscreen with 2 monitors plugged in and clicked on the second moniter since it didn't constrain the cursor to the game screen.

Fun times...

 

[SonOfVoorhees]

Dead Island. Was a part where you have to get petrol, transport them in a vehicle and put them onto a boat. The game wouldnt let me put the cans on the boat so couldnt progress any further. Never replayed that game again.

 

[Tahaneira]

The most recent one I encountered was when I was playing Ori and the Blind Forest. In the last dungeon, you have to plug lava falls with rocks in order to lower the lava in the main rooms to proceed. Except that after plugging one gap I returned to the main room to find that the lava hadn't lowered at all, thus rendering me incapable of continuing. There's no way to bypass it, and since the game has a checkpoint system instead of saves there's no way to restart the temple. The bug was eventually fixed, but saves that are already bugged remain bugged, so I have to start the whole damn thing over again from scratch, including all the exploration and item collecting.

It's not a long game by any stretch of imagination, but still. I haven't had the heart to go back and do it all again yet.

 

[Redd the Sock]

I have one right now that's a bit literal. Copies of Hyperdimension Neptunia re:birth 3 shipped to stores in Canada won't install at all on the vita making the game literally unplayable.

Only thing I recall in game was Lego Harry Potter years 1 - 4. Before it was patched, if you grabbed one of the character unlock tokens in the dungeon of the castle hub in the wrong way the game would autosave and trap you in the dungeon with no way out. Someone actually found a bug to get out by switching certain characters on one side of the screen.

 

[chadachada123]

There's a bug in Oblivion revolving around the Mage's Guild and that star chamber (I forget what it's called) room. One of the quests has you needing to speak with the woman who maintains/works in that room and she's supposed to be found in the main lobby area of the Mage's Guild...however on some playthrough's she's in the star chamber and absolutely will not come out. This is a problem because the door is locked with a key, and thus cannot be picked...and the only person with a key to that door is the very lady you need to speak to. As such, on some playthroughs, it's impossible to complete the Mage's Guild questline.

That reminds me of my friend's tale, and how he never was able to beat the Mage's Guild. For some odd reason, the final boss for the quest line somehow turned on no-clip, and my friend had absolutely no way to damage him. He's still mad about it to this day.

Me, my most notable one that I can remember is in FarCry 2. In that game, your character has malaria and has to take malaria pills every ten or fifteen minutes or so. Eventually, you run out, and have to find a resupplier before you freaking die. Unfortunately, sometimes, the resupplier does not spawn, dooming you to constantly die every twenty or thirty minutes (they give you a chance to not die before the next wave of malaria kills you).

Being several hours into the game by that point, I said screw it. No way was I going to risk wasting another few hours to see if the guy will spawn. Ubisoft never patched it, either.

 

[Johnny Novgorod]

Too many in Arkham Origins to count. Interrogations won't trigger, Deadshot vanishes mid-beatdown, 'Bird' mission is glitched, etc.

 

[Someone Depressing]

In the original Shin Megami Tensei, the game gave you an alignment around 1 quarter in, composed of two parts:

A morality, either Dark or Light. Fairly self explanatory: Dark demons are assholes who take all your money then run away, Light demons are cool with humans and are to negotiate with.
And a faction: Chaos, Law, or the third - and sanest - option: Neutral. Each faction has exclusive weapons and demons, except Neutral.

At certain points after the game becomes non-linear (about 30% in) you are sent into specific plotlines depending on your alignment, but the game never "locked" you in, meaning that if you accidentally changed alignments during these branching plotlines you were pretty much fucked.

 

[Xeros]

I remember when I finally buckled down to actually finish the primary Skyrim questline, doin' my utmost to not fall back into sidequest limbo, Esbern refused to open the door. It was right back into limbo for me, and to this day I've yet to complete Skyrim.

 

[StatusNil]

In Assasin's Creed 2 there's a cutscene where you're pulled out of the Animus briefly.
If the game is turned off during the cutscene then when you reload you're stuck in a warehouse as Desmond with nothing to do, and no way out.

Indie GOTY material, clearly.

OT: Neverwinter Nights 2 was one bug-ridden mess, even after it very slowly (at the time) downloaded what I remember as about 20 patches individually. Events failed to trigger left and right, but the one that got me was an endless loading screen when entering a crucial area. I went back through all my save files to see if it still occurred when starting at those points, and it did. Luckily several months later when I restarted I managed to complete the game, though missing some side stuff that didn't work on that playthrough. Ah, memories...