Although countless buildings are visible, most are a facade, and don't actually contain interiors at all. (Just about any non-RPG game.)
All women are strong, agile, independent, and skimpily dressed. (DoA...)
Most can take sword strikes to the anywhere and survive. (Soul Calibur)
Several sword strikes. (Or Ninja Gaiden...)
And a grenade. (Unreal Tournament)
When all else fails, the pistol usually has unlimited ammo. (Just about any arcade shooter, be it lightgun or sidescroller.)
There are two types of food:
Instant Health foods.
Slow, Steady, and Ultimately more fulfilling regenerative foods. (Various MMOs.)
You can only die forever if it is scripted in the storyline, or until you restart the game.
Touching a star will not instantly sear off or destroy any part of you, it will instead render you invulnerable to all hazards except endless drops.
It also makes you run faster.
Despite creating countless super-killer robots, Dr. Light has yet to figure the exact metallic alloy that is immune to spikes, much to any of his creations' demises.
No matter what laws of physics need apply to humans, these physics will rarely, if ever, apply to martial artists and ninjas.
Even though it has molded to the point of having a fully grown mushroom, bread is still edible for up to 10 points. (Metal Slug series)