The Perils of 250

I've learned the hard way that "250" can be a very dangerous value in
Blades of Exile.

The scenario editor's instructions tell you that setting a Stuff Done Flag
(SDF) to the value of 250 has two effects: it makes a white circle vanish
from the screen (if there was one), and it tells the game that this
particular special node cannot be activated again. That's all well and good
but it has one other peculiar effect, too. Sometimes--all the time? I'm not
sure yet--setting an SDF to 250 can screw up a complex chain of events.
Example: You have a "Give Special Item" special node which gives the party
a Cursed Amulet. If the party has the Cursed Amulet and they enter the Trap
Room, the ceiling collapses on them and they take damage. If they enter the
Trap Room without the Cursed Amulet, nothing happens.

One way to do this is like so: the "Give Special Item" node which gives the
Cursed Amulet jumps to a "Set Flag" node which sets Stuff Done Flag (C,A)
to 250. The white circle disappears--yay! The party can't get the Cursed
Amulet twice--yay! So then the party enters the Trap Room and they step on
an invisible node: an "If-Then" node which checks the value of SDF (C,A).
If Stuff Done Flag (C,A) > 0, (which it is because it's 250), drop the
ceiling on them!

Sometimes this fails. The party has the amulet but the ceiling doesn't
drop. Why? I think it's because "250" isn't always a recognized numerical
value in Blades of Exile.

In other words, B of E can't figure out that "250" is actually greater than
0. "250" means "make the white circle disappear", but "250" doesn't seem to
mean the NUMBER 250.

How do you resolve it? Like this:
Party gets Cursed Amulet: Set SDF (C,A) to 250 to remove the white dot,
etc. JUMP TO another special node, in fact, another "Set Flag" node, and
now set SDF (C,A) to "1" (or "2", or whatever--just not "250").
While playtesting my scenario-in-progress "Islands of the Wheel", I've run
into this phenomenon four times, on four separate occasions, dealing with
four entirely different situations. But they all had two things in common:

1) They all had a "Set Flag to 250" command somewhere in the chain of
nodes, and
2) Either removing or replacing that command, or keeping it but then
following it with a "Now set the same flag to 2" command, always worked to
clear up the problem.

The real bug here is that sometimes, 250 seems to work okay. It does when
I'm testing one little piece of a scenario. But once the scenario gets big,
strange things happen.

Until I understand this situation better, I make the following
recommendation to all designers: Set an SDF to 250 only when you want to
remove a white circle, or when you are POSITIVE you will never have to
refer to this flag again. If you must set an SDF to 250 to get rid of a
white circle, then follow that command immediately with a node that sets
the same SDF to 2, or 5, or whatever number you like, as long as you
remember what it is. That way, if you have to do an "if-then" node which
checks the value of that SDF, you'll get a reliable result.

--Tarl Roger Kudrick ,
tarl@access.digex.net