Fun fact: Getting kills with the Masterkey amounts to kills with the Super Shorty. I'd imagine this applies to the M203 and it's under-barrel counterpart.
The main reason why "thou shall not walk left" is so funny is because it makes you feel like a complete idiot after you realize what you're supposed to do.
It was a nice touch to make party members with fire resistance actually take less damage when walking on lava with the thermal boots,and ones that are weak to fire.