Updated Wed, Jan 16, 2013 by gunky
Dynamic combat is featured in a number of newer games - Guild Wars 2, for example. It relies on positioning and facing. You need to keep your enemy in front of you, within the arc of your attacks, and you must react to your enemy's attacks to block or dodge. Combat is fluid and natural-feeling, far more realistic than tab-selecting your target and hammering on the number keys to deal damage. There's nothing inherently wrong with that system - it's still being used in many major titles right now - but it can't compare to the visceral thrill of lining up that perfect headshot with your bow, or finding just the right angle to take out three enemies with one swing of your greatsword, or of getting that shield up just in time to catch the crossbow bolt streaking towards your throat.
This kind of fluid, reactive combat has its downside, of course. With this style of combat, twitch reflexes play a fairly significant role. You have tiny fractions of a second to get that shield up to block an incoming blow, or to leap out of the way of a fireball. If you lag, you take the full force of the blow. This gives players with very low latency an edge, and players (like me) with very high latency a distinct disadvantage. 200 milliseconds is an eternity in 1-on-1 PvP battles.
There are, of course, a lot more reasons to check out the Elder Scrolls Online when it goes live later this year - social networking integration, awesome voice-acted NPCs, and cool new phasing technology, just to name a few things - but these are our Big Five. What are you most looking forward to? Let us know in our comments!