it's a set of weaponinfo.xml mods
each difficulty has correspondent explosionfx.dat
all mods are basen on my previous mod, and therefore they use sledgehammer instead of baseball bat.
Icon for the sledgehammer is scheduled to be downloadable as a separate file.

easies dificulty comes in 2 variants:
 *no damage from guns nor explosions
 *almost no damage and lots of physics

realistic comes in 3 forms:
 *realism of ammunition and damage
 *specialisation on RPG
 *variant with realistic recoil for player(R* cheated us and made Niko
 much more accurate than people, as outcome this variant makes other people too damn inaccurate)

hardest morphs in 2:
 *no chance of survival
 *extreme damage and extreme physics

anyone who's ever thought of any of following qustions will find what he wants:
what if IV was terribly easier? or impossible? or much more realistic? how long can i last if one shot=death? what would i do with lots of force and no damage?

In case you wanted advanced realism, I reccomend to use the following mods:
smoother trees, etc. http://www.gtagarage.com/mods/show.php?id=5721
or my variant for medium textures http://www.gtagarage.com/mods/show.php?id=6371

ragdoll euphoria http://www.gtagarage.com/mods/show.php?id=5714

realistic driving and flying http://www.gtagarage.com/mods/show.php?id=5529

realist physics http://www.gtagarage.com/mods/show.php?id=5350

ultimate graphics tweak http://www.gtagarage.com/mods/show.php?id=5691
or
gta realistic environment(if you use 1.0.3) http://www.gtaforums.com/index.php?showtopic=397854