Tuesday, July 05, 2011

Cheating AIs: X-Com

I got the urge yesterday while watching Independence Day to play X-Com: Ufo Defense. I've never actually completed this game and not having done so bothers me. It's a pretty hard game but it's not impossible by any stretch. I started a new game up last night and ran into the cheating AI on the very first fight which was frustrating.

The game has two main parts to it. The first is a city building, tech researching, money making game on a map of Earth. Sometimes some alien UFOs fly by your radar stations and you can send a ship out to shoot them down. Or sometimes the aliens just land to pick up some cows or terrorize a city. Once the aliens are actually on the ground you can send a troop transport to go engage them in a turn based battle. The game simulates day and night, so it's possible this turn based battle will take place in the dark. This drastically reduces how far you can see for both you and the aliens. However, once one of your guys can see an alien the rest can shoot at him regardless of distance. That's a little weird, but I guess they didn't want to worry about adding ranges to all the weapons and deciding what happens when a laser beam travels beyond max distance. At the end of turn you lose these established locks on the aliens though, so if they manage to kill your scout on their turn you'll need to move someone else forward to see them again.

If it worked both ways that would be fine. Unfortunately the aliens cheat. They need to actually see your guys before they can shoot them just like you do, but they don't lose their target lock at end of turn. The higher the difficulty, the longer they can still see you. This can set up some absurd scenarios. If the aliens have one guy who can see into your ship at the start of the map you'd be in serious trouble. Every alien unit can now shoot at all of your guys for turns and turns. Snipers can be really hard to find and destroy since they can attack you from huge distances, well out of your line of sight (especially at night). Later on in the game you fight aliens that can cast mind control spells through walls. Some grunt saw you 3 turns ago? Legal target for mind control from the other side of the zone! There's also a weapon that's essentially a remote control rocket launcher which you can program 9 waypoints into so it can move around corners and down elevators. These can be huge problems and a lot of the micromanagement of later combats is making sure you can't get screwed too badly by these things if the AI decides to actually abuse the powers it has. (Often it doesn't with the rocket launchers. The mind control it will abuse all day long.)

What happened yesterday is I did a fight at night because I was afraid the site would despawn if I waited for day. One of my guys caught a glimpse of an alien right at the edge of her movement. She shot at him and missed. Then on his turn he took off in the other direction. Do I chase? If so I need to run across an open zone where the enemies can see me and take attacks of opportunity on me and I can't fight back until I get in range. I ended up running 3 guys in the direction of the 'hidden' alien and managed to kill it after losing only 1 to attacks of opportunity. He sucked anyway, so not a big deal, just annoying.

Like in most games I don't know how you would fix it though. It's a brutally powerful advantage (let me control the aliens and Byung control the humans and I'd crush him) but the AI just isn't good enough to abuse it properly. Maybe forcing me to have all my guys immune to mind control (hire hundreds of dudes, train them in psionics, and fire any with weak psi abilities) is a reasonable price to pay to have an AI that scales somewhat?

No comments: