funny thing unrelated, but funny so included here, because it makes you think.
a few years back there was a game released, Temple Of Elemental Evil (henceforth Temple).
This game didn't do well, but it received some praise from some gamers (i.e. some people LOVED IT, most hated it).
It was based on the older rules of AD&D. And you played a full party.
This meant that it had a lot of options, but also that it was slow, and unwieldy, and hard.
You started from level 1, and were expected to reach maybe level 12, which is not much. However, most of the engine was in the game, so if you were ready to grind, you could reach a higher level.
Now .. the game used 100% pure AD&D systems.
If you started the game, ran into a badass random encounter ...
And killed them all except one ...
and all your characters died .. except one ..
and then your last character killed that last mob ...
BOOOOOOOOOOOOM instant level 5 or so.
because the number of mobs would generate a threat level, which would assign a XP value to each mob. But because all your characters died, the game would think it's your 1 character vs all the mobs, and raise the XP value of each mob.
And because your characters were dead, you would not have to share this XP, but it would all go to your 1 character left alive.
And then you could go on and now you were higher level, and you would just wreck all the mobs, and keep on getting boatloads of XP, and totally break the character level ceiling.