Dungeon Master Forum

Type: Bug
Category: Monster AI

This has already been hinted at in another thread, but I thought I'd make a new post about it. Creatures that cast spells now cast their spells onto the tile that they are on, effectively killing themselves. I have confirmed this with Swamp Slimes, Beholders and the Dragon.

This bug causes a crash if they kill themselves, so don't just stand there and laugh, kill them first! Quickly!

I managed to isolate this last night - if I get a chance to re-build everything tonight hopefully V0.15 will be out tomorrow!

For those of you that are interested, this is the logic flow that causes the problem - Monster decides to cast a spell. Monster casts a spell. Spell is added to tile, pointing towards the party. Collision detection routines kick in and spot that there's a spell on the same square as the monster. Spell detonates - doh!

But does anyone have any idea as to why suicides cause crashes? I would think that it is not important WHO kills a monster, it just suffers a specific amount of damage, and *BAM*. Doors can crush the badasses, but the game doesn't crash then (should this be also tested?).

The suicide thing is a seperate issue (although still a bug in the collision detection routines). What's happening is when an object is put onto a tile it checks to see if there's any actions that need performing (pads triggering, monsters/party hitting, teleporting etc etc). How it does this is by building up a list of things on the tile to check against, and then doing the checking. The crash occurs when a monster is destroyed by addition of the object, and then the code doesn't delete the monster from the list of objects to check - when it comes to look through the list it references the monster (which no longer exists) and it all goes horribly wrong...

First off, Mr Gilbert, you are a legend. Thanks for allowing me to relive one of the fondest memories of my youth.

To add my penn'orth to the mysterious crash syndrome, I have noticed this happening a lot, especially as I am now on the treasure trove level with the 'suicide slimes'. BUT, it has happened to me in other places. For example, on the previous worm-ridden level, it crashed out a few times when I attacked monsters with fireballs, and once, it even happened when I delivered a killing blow to a worm with the sword. :/

I hope this is worthwhile food for thought and I look forward to v1.5. Keep up the good work.

Cali

P.S. A change of version doesn't make your savegames unusable, does it? (Fingers crossed).

Fixed for V0.15