I would like to find rules for projections.
When a very strong creature hit someone of medium or small weight I imagine that this someone could be projected some distances away because of the impact.
But i never found a rule to represent that.
Any existing rule in the game ?
Or if not any house rule ?
There is an ability to represent this, called (I think) powerful blow.
There's even a monk archetype that can get it.
If you want more of that, you could give it as a houserule to all creatures with size over large, or with strength over 40.
Rules exist but your using very weird language for it.
I don't think anyone would call that "projection".
Regardless, in Pathfinder it's called awesome blow.
If you search the PRD for awesome blow and look for creatures you will find lots of creatures with the ability.
Hes probably not a native speaker. Trajection ? ;-)
I think the OP is talking about what Hero System would call "Knockback".