Don't impose imaginary combat limitations please

You being weak enough to the point having a shield at your side effects your speed versus a raised shield is NOT research, it's you being weak and untrained in the use of shields. You move slowly when a shield is raised for one easy and very real reason: You need strong footing and balance to withstand the force of the blocked blow without getting knocked back and falling on your ass or more importantly breaking your arm. The shield isn't what slows you down, your character is using the shield properly and moving slowly to keep his/her balance and footing. It's not artificial.

The only problem here is that you don't like it. In which case I must retort: Deal with it or mod it. It's an accurate drawback for using shields.

 

Good thing this isn't real life right? Anyway what @Xendhaius said is accurate so it is realistic...

 

thats like one of the laws of video gaming. When a character holds a shield, they become less mobile.

 

You ever used a shield in a fight? Speaking from experience, it's very hard to run full-tilt and still get your shield into position to block incoming blows. Yes, characters in Starbound just hold their shield in front of them in a static pose, but this is an abstraction for gameplay purposes. In real life, you'd be moving that shield around to put it in the path of all the sharp, hot, pointy, or otherwise-dangerous things flying in your direction.

A shield could weigh anywhere from 4 pounds (for a lightweight 2-foot diameter police riot shield) to as much as 22 pounds (for the thickest Roman-style scutum). Most medieval European shields (which the bulk of shields in Starbound seem to be based on) weighed around 8 pounds. That might not sound like much, but keep in mind that it's not static. In close-combat, you're constantly moving the shield around to interpose it between you and incoming attacks. That's a lot of work, both physically and mentally. Unless you're just holding up the shield in the general direction of the enemy as you run by, and hoping that the shield gets hit instead of you, or fighting in a phalanx where you and your buddies form a veritable shield-wall of coverage (impossible in Starbound as players cannot line up abreast properly due to the 2D environment), you're probably going to slow down.

There's also this. I don't think I could put it much better than Xendhaius has.

I don't see it as an 'artificial' limitation at all. Just a slight abstraction of something that genuinely occurs in real life.

 

Skyrim has the ability to let you run while your shield is up. Granted, this can only be achieved after you have spent considerable time training how to block. Since there's no hefty RPG mechanics in this game to allow training certain aspects of yourself, you're just gonna have to deal with hindered movement while the shield is raised.

And besides, it's not unrealistic. When raising your shield, you immediately assume a defensive stance. You ground yourself, gain stable footing which you will need in order to not get knocked around while you're blocking what could be heavy attacks. If a monster your size or larger charges or body slams you, and you didn't assume a defensive stance while blocking, I can assure you that your shield arm is going to break or your body is going to get crushed under the monster's weight. That's from a realistic standpoint, but it's still valid nontheless.

 

An additional mechanic involving shields would be nice. When you hold it up a circle appears and begins slowly draining (clockwise color fade wedge). If you take a hit, based on the damage of that hit vs. the effectiveness of that shield the circle drains more. If you move (at full speed), the circle drains much faster, and if you hold shift (the walk/precision button) and move it continues to drain at the default rate.

A system like this would make it so that shields have limitations, but also added possibilities. More ways to play always seems better to me than less, and it means that shields wouldn't be used with your energy.

 

I like how it slows me down actually. Makes me feel like a tank.

A shield slam attack that knocks enemies back would be very cool, though. Just throwing that out there.

 

Ok so you can dual wield

I've been wanting an excuse to actually run double shields...

 

If you had, in fact, done your research you'd understand you're not simply holding a shield in front of you. You're bracing yourself for incoming impacts against that shield, without which you may as well not be using a shield at all as you'll be promptly knocked flat on your ass and finished off. Even boffer fighting, enough force can be involved to cause you to lose your footing if you're not prepared for it.

EDIT:

Personally, I like the idea of technological or mechanical shields that deal reactive damage on a block.