This program helps determine "line of sight" for the Doom and Descent board games from Fantasy Flight.
In these games, you compute line of sight by checking to see if a line can be drawn from the center of the attacking square to the center of the target square -- without touching any obstacles along the way (except for touching the corner of an obstacle).
For purposes of spawning, you must look for an area in which no Heroes have line of sight, and Monsters do not block the Heroes line of sight here.
Here is the full map of Descent's Quest 3, with some Heroes (in green) and Monsters (in red). Yellow squares indicate where the Heroes can attack, and olive squares indicate where the Heroes can't attack, but the Overlord still can't spawn there. This is because Monsters block line of sight for attacking other Monsters, but not for spawning.
Notice that the first door has been opened, but the other doors are all closed. Also notice the "Spawn Mode" option is active. This shows where the Overlord can spawn, and also shows which Monsters are out of line of sight from the Heroes.
If a figure wants to attack, and there's some question about what other figure(s) are in line of sight, simply Alt+Click on the attacking figure. This puts a red box on the attacker, and puts yellow boxes on all spaces that are in line of sight. The following picture illustrates this (the attacker is the monster guarding the closed door to Area 2).
The next picture shows Attack Mode for a Hero. In this case, the Hero can only target the adjacent Monster -- the others are all out of line of sight.
One of the more complex features of the game is the Crack Shot skill. This one lets you trace Ranged attacks from any adjacent empty space. This means that if your desired target isn't in line of sight from the space your Hero occupies, you can check line of sight from any of the eight adjacent spaces (the empty ones at least). Talk about time-consuming! Well, that's what the "Crack Shot" option is for. It is only usable when you have selected a Hero for Attack Mode. The following picture shows how Crack Shot alters the situation from the previous picture.
Now that the Hero is using the Crack Shot skill, he can target two of the Monsters, instead of just the one. Isn't that cool?
Well, Precision is another one of those complex skills. It lets you ignore a single blocking obstacle (basically, rubble or another figure) when tracing line of sight. Look for "Precision" mode in a upcoming version of Line Of Sight.
This program is free, and you can download it right now. It runs on Windows.
You can create your own maps, save and load them, share them with other people, etc. The maps are stored in plain text files. The program comes with the full map for Descent's Quest 3 and 4. When you run the program, just hit F1 for help on using it.
Questions? Comments? Let me know.