Simple mod that makes you ragdoll if you're standing on sublevels that are tilted. Running/moving makes you fall down easier, sneaking/standing still makes it harder to fall.
This mod also tilts all entities that are standing on sublevels, this way, it looks like they're actually standing there.
Ragdolls also try to balance themselves, kinda like GTA 4's Euphoria Ragdoll system
All angles are configurable in the config.
If you are building a modpack
you might be interested in some of my other mods for modpacks: AttributeSetter RPGDamageOverhaul FoodAttributes
Or Claims n Raids for servers/smp!