Since there's currently no manual for the game, can anyone provide me some basic advice on how to play the game and not be terrible? (And/Or a PDF of the manual?)

I played this way back on the Tandy 1000...wow, I'm old. Computers have gotten a lot faster since then. I mean, just yesterday, my cell phone was...oh. The game. Right.

Well, for basic advice, I'd check out this wiki site on the game: http://covertaction.wikia.com/wiki/Covert_Action_Wiki. Get to know the plots, and you'll start to get a feeling for who you need to go after.

Practice your minigame skills. Get a feel for the controls.

You always want to go after the mastermind.

You always want to find evidence that will make someone a double agent. This is usually found in a floor safe at their hideout if it exists.

Move fast; most plots are completed within a week.

At higher levels, you'll have double agents at the CIA to deal with. They'll feed you misinformation. Pay close attention to WHERE the intel comes from and when you spot bad intel (through further research), you'll be able to bust them.

Just be careful of looking too much at that Wiki, as it explains a bit too much of how the plots work internally, which can ruin the fun for some -- trying to understand what's happening in the plots is half the fun.

My advice is play it and expect to fail. However, when it goes through the plot overview, try to see what's going on and what you missed. Until the higher levels, all the clues you are given are important.

My biggest problem when starting was not knowing what the withdrawal clues were trying to say. Well, money is withdrawn in order for someone to either buy something, or to pay for someone's services. So follow the money is a good advice.

Finally, you generally don't want to actually stop the crime until you know who most people are. Stopping the crime usually causes people to go into hiding, which is bad. Instead, either turn important people, or try to judge when someone no longer is important to the plot. When that happens, arrest them before they go into hiding.

Have fun -- I absolutely love this game, and it's such a shame it just never took off.

Start a game on the easiest setting. Immediately start breaking into places and taking photos / bugging things / shooting people / chucking grenades.

Seriously - play through at least one madman-style spree to learn the controls, especially during the building infiltrations. Mess up a few wiretaps / vehicle tracking submissions.

Wiretapping will provide information over time, assuming you target the right buildings. Infiltrating a building before you're ready to take out its occupying agent can get hairy - raise the alarm and it'll be heavily guarded when/if you come back. On the flip side taking photos of desks and wall safes is maybe the quickest way to get information. If an agent for a particular group is active in an area then target that building, obviously (if you know where it is). If you're completely lost try targeting the buildings of the primary group even if you're unsure which cities their group is being active in.

Green grenades are gas. Red are fragmentation (lethal). White are concussion.

During the infiltration missions, or when you are ambushed, the numberpad controls your movement. 5 toggles walk and crouch - you can crouch to avoid detection. So can they once they're aware of you (grenades are your friend at that point). The regular arrow keys make you leap in that direction, which stops your movement for a second but lets you cross over furniture and ends in a crouch. If you are facing a visible enemy a crosshair appears in your picture - slap FIRE when this happens. I think a white crosshair is a guaranteed hit.

You win when you capture the mastermind. You lose when the plot is completed. The middle ground is preventing the plot but allowing the villain to escape. During the post-op investigation there's usually a clue or two as to the mastermind's identity that gets discovered - the most sure but least exciting method of winning is quickly taking out a critical link in the plot and then waiting for things to wrap up. Done a handful of times this'll eventually allow you to target the Mastermind directly. But it is more fun trying to figure it out while on the case than letting the post-op team handle the intel gathering.

Combat tips : Don't throw gas grenades if you're not wearing a gas mask. Sounds obvious, but it happens. Consider booby-trapping funnel points like doorways after the shooting starts (F10). Always take the vest. You can get grenades mid-mission by shooting the guards, so they're usually safe to leave behind (unless you're going in hot to take out a predetermined target and don't care about getting any information) The headphones let you hear when enemies are in adjacent rooms and might even be more important than the vest. You can throw grenades through doorways. The enemy will do the same. Gas grenades will take out an enemy before he crosses a room, but not before he shoots you full of holes - use it to temporarily close off the rooms they need to travel through to get to you. Gas is more about area denial than straight offense. Touching an enemy will kill them and do one damage to you. Even with the vest you can just take four or five shots - if they hit you with a concussion grenade they'll usually stroll up and take you out before you get your breath.

You could watch the ADG video I linked to in another thread, he explains the basic gameplay.

I have found out I always take the same load-out - kevlar vest, motion detector, camera, safe cracking kit, with only one deviation - if I expect tough, ready opposition or make arrests, I take uzi instead of the bugs. If not, I take the bugs and bug all the rooms I can get into.

Also, during covert break-ins, cover your tracks. Re-close cabinets, doors, everything. Guards will sound alarm when seeing something suspicious.

If you have a disguise, you are safe as long you are turned away from the guard - use it to your advantage, and shoot when he turns away.