Combat in Cube World is based on player skill, movement and reaction. Skilled players can beat high-level monsters, while not-so-skilled players can be beaten by low-level creatures.
Manual Aiming
Enemies need to be targeted manually with a crosshair. There's no target locking. Good players will land more hits and thus deal more damage.
Active Dodging
Most attacks can be dodged with good reaction and proper timing. Dodging costs stamina and makes you immune against damage for a very short time. With skill and good stamina management, you can survive even the strongest attacks.
Combos
All creatures have armor and resistance. Armor decreases physical damage, resistance magical damage. Every time you hit an opponent, you get a combo point. The more combo points you have, the more armor/resistance of your enemy is ignored for your attacks. So if you succeed to build up enough combo points, you can penetrate even the heaviest armor.
Aggro
Aggro is basically what determines who an attacking mob attacks. When a player hits a mob, that mob's Aggro goes up for that player. A mob is more likely to attack those with higher Aggro. Melee attacks generally produce more Aggro than long-ranged attacks. Aggro may be affected by how far away a mob is.