We are predictable creatures. If left alone we fall back to our habits. How does this affect gaming? Well if we fall into habits we're prone to select one outcome more often than another. Reach a comfort zone, become a bit reiterative and lose narrative potential.
Randomness, particularly die generated randomness can help a lot in moving away from these habits, to unload a great deal of the GMs burden on the dice and grant the GM more time to concentrate on what matters most: the story. But it is also a potential curse. If instead of unloading burden onto the dice we begin to run the game with dice we loose all narrative potential and the adventure becomes a series of unrelated events. Let me explain a bit further.
There are some things that need to be determined in the game and should be random. For example the hit points of the goblins. If all goblins had the same hit points combat would be extremely predictable. But actually having to think random numbers is an unnecessary burden for the GM. It is better handled by dice or any other random generation mechanism. Should there be 7 or 10 goblins. Just roll some dice and let them sort it out. This is an important tool, but not the one I want to concentrate in this article.
There is more to dice than just setting some level or value. Die rolls can be successful checks or strikes, near misses or total flops. Die rolls can be near saves. The character fails the throw, but barely. This buys him a bit more time. The pick locks manages one turn, but doesn't fully open. The picks and tools break or get stuck. The fighter misses by so little she cuts some hair of the orc's head. Dice don't need to be interpreted as yes/no, success/failure or other absolute values. Some games already contemplate this in their rules, but others don't. For those that don't I recommend you think die roll as partial success or failure as well. It adds a great deal to the story. The narrative is greatly enriched if you leverage that extra bit you get from the dice.
And for heaven's sake don't let dice take control of you adventure. Personally I recommend cero random encounters. If you do, use the dice as inspiration. You meet what? Centaurs ok. It's not necessarily a combat encounter. What random encounter tables can't tell you is what they are doing there. Are they traveling, what are their interests. What would you do if you were a centaur and this happened. Random encounter tables can be good to get you thinking before the game. During the planning phase. Kick start your brain into thinking possibilities. Roll some encounters. Imagine them. Let them break you away from that comfort zone. Sleep on the idea. Then settle down and make a real fleshed out encounter out of it. To just roll random encounters during the game is in my opinion narrative suicide. Stay away from it.