As there are abilities such as freedom and anticipate, which can clear DoT hits and stuns, allowing you to escape from a Pker if necessary or effectively fight back. Player versus monster situations are not balanced.
Either In the game OSRS Gold there are buffs that can be activated called prayers. Such as protect from melee, protect from magic, and protect from missiles. In Old School RuneScape, these prayers prevent 00 percent of incoming hits in these combat styles.
Which makes you completely immune so long as you have some way of restorying your prayer points, the fuel by which these buffs are perpetuated. This is completely overpowered and in RuneScape , these prayers only prevent half of the incoming damage and are effective in some places.
But do not make you literally invincible. Not only this, but buy OSRS gold combat is simply boring in Old School RS. It consists entirely of clicking on your enemy and watching you slap it periodically with your weapon. That's it.