MISSIONS.DAT
contains counters and race info on the ongoing acts. At the start of the game (beginner level) research in your home zone and terror in a random zone is initiated. After that each new month you will get two new missions, one of which is a terror mission (beginner level).
Structure of a mission entry
Each mission has 4 words. With 7 acts on 12 zones these are 672 bytes. E.g. infiltration(3) in Europe(4) would have the offset 3*8+4*(7*8)=0xF8.
offset meaning 0 ufo-counter on the ufos within the mission (FFFF, the mission is not active) 2 sub-ufo-counter used for some missions 4 time-counter, 30 minutes to next ufo 6 alien race of mission
The race number can be looked up in ENGLISH.DAT, entries 466-476:
0 Sectoid 1 Snakeman 2 Ethereal 3 Muton 4 Floater 5 Celatid 6 Silacoid 7 Chryssalid 8 Reaper 9 Sectopod 10 Cyberdisc
Timetable of a mission
When a mission starts, the ufo-counter is set to 0 and the time-counter to some act-depending time. The time-count is reduced every 30 minutes. When 0, an ufo will appear, the ufo-counter (or the sub-counter on some mission) will be increased and a new random time-counter for the new ufo will be set.
Note on the timing
Battlescape missions do not affect the scheduling of future UFOs.
UFO appearances are established with a base time period to which a random amount of time derived from the base time is added. The effect is that a UFO arrival will be scheduled 50-150% of the base time. When the mission is created, the first UFO in the mission is spawned when the timer reaches zero. Then the mission entry details are set for the next the next UFO in line and the timer begins counting down again.
Shooting down a UFO will immediately add 24~224 hours (1~9 days) to the timer for the next UFO in that mission. Tycho (talk)
Research
ufo-c time-c ufo-type 0/0 150h s.Scout (start of game Research mission is 2.5h*. This is for later ones) 1/0 130h m.Scout 2/0 150h l.Scout 2/1 150h l.Scout
Harvest
ufo-c time-c ufo-type 0/0 130h s.Scout 1/0 130h s.Scout 2/0 100h m.Scout 3/0 130h l.Scout 4/0 150h l.Scout 5/0 50h Harvester 6/0 12.5h Harvester 7/0 25h Battleship
Abduction
ufo-c time-c ufo-type 0/0 250h s.Scout 1/0 300h m.Scout 2/0 150h l.Scout 3/0 150h Abductor 4/0 1h Abductor 4/1 1h Abductor
Infiltration
ufo-c time-c ufo-type 0/0 275h s.Scout 1/0 250h m.Scout 2/0 230h m.Scout 3/0 150h l.Scout 4/0 1h l.Scout 5/0 1h Terrorship 6/0 1h Supply 7/0 1h Battleship 7/1 1h Battleship
after this, the mission does not end, but starts again with ufo 0 again.
Base
ufo-c time-c ufo-type 0/0 1w s.Scout 1/0 1w m.Scout 2/0 1w l.Scout 3/0 1.5h* Supply (but shooting it down is worth ~1w of delay anyway) 3/1 1.5h* Supply (untested: is shooting this down worth ~1w of delay anyway?) 4/0 0.5h* Battleship
Terror
ufo-c time-c ufo-type 0 2.5h* m.Scout 1 1w l.Scout 2 1w Terrorship 3 1w Terrorship
Landing sites of Terrorships are terror missions, not ground assault missions. Your radars don't want to track a Terrorship after it drops off its cargo. Shooting down Terrorships is highly recommended.
sub-ufo-c is empirically always 0 for Terror acts.
Retaliation
ufo-c time-c ufo-type 0/0 50h* s.Scout 1/0 ? m.Scout 1/1 32h* m.Scout (add 146.5h* if 1/0 shot down at first turning point) 2/0 52h* l.Scout (add 3d if 1/1 shot down at first turning point) 2/1 ? l.Scout 2/2 3d l.Scout (Not always...finally confirmed it could happen, no idea what factors control this one's existence.) 3/0 2d Battleship 3/1 2d Battleship
Zaimoni: Don't have exhaustive information on how these get initiated, yet. Hyperwave detection doesn't rewrite mission types on the fly, so I have no idea why I'm never seeing these scheduled other than after a successful shootdown (alien base mission not verified either way yet). NKF has seen these as very first mission...perhaps this is a version difference? 0/0 time-c is for retaliation acts scheduled in response to shooting down UFOs.
Unlike the others, many of these times are not measuring random at all. There may be variance between games, or other factors, but certainly no random variation for a given UFO when a sharp time is recorded.
Shooting down a UFO immediately after it slows down "post-entry" [within the same half-hour block] schedules these unreliably. (At least, this is about the only time I see it. Empirical probability...somewhere around/under 10%, don't have a large enough sample to be more precise.) The time that can elapse while still triggering this is not fully known, and may depend on prior BattleScape results and/or various aspects of the scoring system.)
Using the information
You might find that may small scouts appear at 2:30 on the first of a month. This is due to a often found count of 5 with the first ufo on a new terror mission for the month.
To make use of this knowledge might be difficult. But say, if you see a supply ship at a location without an alien base at the end of the third week of a month, it might be on a base mission. Then you should expect a second supply ship and a battleship somewhere close. If it is on infiltration you might see two battleships. If you see a first harvester/abductor, watch out for a second within three days. With a hyperwave decoder you might have more use from the mission sketches.
See Also
- ACTS.DAT - Contains actions the Aliens will embark on
- ALIEN.DAT - Contains alien activity for graphs
- ZONAL.DAT - Contains priorities for alien activities
- UFO Flight Patterns
- Game Files