More 5e Rogue weirdness: bonus actions and movement

 As we've noticed before, there are three meta-classes in 5e; you can call them warriors, experts and spell-casters. The rogue is the only expert (and maybe the bard is a "half-expert"); everyone else is defined by their attacks or spells.

What do experts do? Anything else. And how do they do it? With bonus actions.

Source.

This is, plus sneak attack (which relates to this) and expertise, what defines rogues:

Cunning Action 

Starting at 2nd level, your quick thinking and agility allow you to move and act quickly. You can take a bonus action on each of your turns in combat. This action can be used only to take the Dash, Disengage, or Hide action.

Rogue subclasses have even more options. This is from the Rogue: Inquisitive from Xanathar's Guide to Everything: 

Eye for Detail 

Starting at 3rd level, you can use a bonus action to make a Wisdom (Perception) check to spot a hidden creature or object or to make an Intelligence (Investigation) check to uncover or decipher clues.

Insightful Fighting
At 3rd level, you gain the ability to decipher an opponent’s tactics and develop a counter to them. As a bonus action, you make a Wisdom (Insight) check against a creature you can see that isn’t incapacitated, contested by the target’s Charisma (Deception) check. If you succeed, you can use your Sneak Attack against that target even if you don't have advantage on the attack roll, but not if you have disadvantage on it.
This benefit lasts for 1 minute or until you successfully use this feature against a different target.

And this is from the Swashbuckler (also from Xanathar's): 

Rakish Audacity 
Starting at 3rd level, your confidence propels you into battle. You can give yourself a bonus to your initiative rolls equal to your Charisma modifier. You also gain an additional way to use your Sneak Attack; you don't need advantage on the attack roll to use your Sneak Attack against a creature if you are within 5 feet of it, no other creatures are within 5 feet of you, and you don't have disadvantage on the attack roll. All the other rules for Sneak Attack still apply to you.

Okay, this last one doesn't require a bonus action, but gives you another way to get sneak attack.

Tasha's guide decided to cut the middleman: use you bonus action and don't move, and you get advantage (and thus sneak attack). For ALL rogues:

Steady Aim

3rd-level rogue feature 

As a bonus action, you give yourself advantage on your next attack roll on the current turn. You can use this bonus action only if you haven’t moved during this turn, and after you use the bonus action, your speed is 0 until the end of the current turn.

So, the rogue is a mobile character than does a lot of stuff quickly. This stuff - aim, hide, decipher an opponent’s tactics - are usually means to get an sneak attack in. Or you can trade some mobility for better attacks.

Some actions require skill checks... which is fine, because the rogue is good at using skills (expertise).

Anyway, it is interesting to see how the rogue works in 5e. I like it. There are some ways to write a more minimalist version (just trade your bonus action for sneak attack already!) but I'm not sure that this is necessary.

Also, I could see other classes (especially warriors) being able to aim or decipher an opponent’s tactics. Maybe this is something that should be accessible to anyone. But that's enough for today.