Do it this way:
Code:
public plugin_init()
{
RegisterHam(Ham_TakeDamage, "player", "FwdPlayerDamage");
}
public FwdPlayerDamage(victim, inflictor, attacker, Float:damage, damagebits)
{
if(inflictor == attacker
&& attacker != victim
&& is_user_alive(attacker)
&& get_user_weapon(attacker) == CSW_KNIFE)
{
SetHamParamFloat(4, damage * 3.0);
}
}
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