Treat Server-Sided as "reliable" objects that affect Gameplay mechanics like Deathmatches, while Client-sided effects are just for "show" and too unreliable to affect game-play. Another thing is that, to
affect Server Sided Objects for everyone you need to make a Server Sided function. Example:
Function serverCmdclearprojectiles(%client)...???
Giving the %client argument to this function will delete the projectiles for the Client player and ONLY that Client player who used it. That player will no longer see the projectiles (yell at me on this if I'm wrong) but still get hit by projectiles though. This is because projectiles are Server-Sided, so if the server tracking your movements and the projectile's trajectory registers that you got hit, it will communicate that to you and override any "false" client-side information you might have. In this case, you are telling the server there are no projectiles, the server then turns around and says "Yes, there are, and you got hit, and now you're dead" and goes about telling everyone you got hit and died, etc.