How does declaring actions work in your game?
 

This is my first read through the rules.

The lowest person in the initiative order has to declare their action before the highest person. So they know exactly what you are going to do. How does that work in play?

Any issues with it?

I do the initiative per PC and NPC..... then go in order of highest to lowest.

Everyone rolls for their PC and as PD I roll for the NPCs...... then I list them in order highest to lowest on a sheet of paper.

Everybody gets one action and then the next person goes..... Those with higher DEX scores get more actions per turn... I work this again in highest to lowest in order of initiative until everyone has run out of actions.

Then a new combat turn starts...... I play 3rd edition though not 4th.

No issues. The person higher in the order is reacting, and someone who is reacting is by definition acting off of someone else's action.

One thing I have done rarely, not often as it is a pain, is ask people to write down their action rather than declare it openly. I then make a judgment call about who can see what they are doing before they declare their action.

For example, PC Able enters a room and sees NPC Charlie just a few feet to his right holding a club, and NPC Baker off in the farthest corner with a gun. Able does not know it, but Charlie is a psycho and Baker is a potential ally.

Charlie has to declare first, and wants to club Able. This action is obvious to all in the room, so I let everyone know it.

Baker declares second, and decides to shoot Charlie. Neither Charlie nor Able can really tell who the swinging gun is going to be pointing at when it goes off, and neither can read Baker's mind. I let Able know that Baker is pointing his gun in the direction of the two of them... and nothing else.

Able now gets to declare his action, knowing what Charlie is doing but not really knowing whether he is about to get shot by Baker, just that it is a possibility. He has to declare based on that imperfect knowledge.

If Baker had been farther away, such that the target was more obvious, I would not have bothered with the paper slips and would have just let Able know the other two actions before deciding.

This may read like some formal process, but it really isn't - it is just a tool to use as needed, and in some form or another I have used it in just about every game system I've used.