[code:1]ex_dmflags # (DEFAULT: 1)
-------------------------
These are bitflags for common game options like Quake's dmflags.

Example:
Infinite ammo and no self damage would be 32 + 1 = 33

Value | Description
------+-----------------------
1 | No self damage
2 | No falling damage
4 | No health regeneration
8 | No armor regeneration
16 | No ammo regeneration
32 | Infinite ammo
64 | Drop weapons[/code:1]

Since self damage is disabled by default you must be talking about "falling damage".
In that case -> set ex_dmflags 3