A small number of spells may be cast as an offense. I have removed saving throws against magic from the game (e.g. why does casting "Light" in the eyes of an enemy to temporarily blind him allow a save, while casting "Magic missile" to attempt to kill not?). So I've added a "to hit" with magic. It works just like spell failure, above.
Adjustments: The use of a magic wand reduces the chance of failure, adding +1 to the roll.
Arcane magic spells cast from a scroll do not fail.
Magicians may use any armor but note that restrictive or iron/steel-based armor raises the chance of spell failure as follows.
|Armor worn||Failure modifier|
The DM should choose what happens in case of spell failure. For instance, a failed Fireball might immolate the spell-caster’s clothes and possessions, or summon a fire salamander. A failed Wizard lock spell might permanently and irrevocably lock the target, or smash it. Whatever happens, it should fit the circumstances and the story that is unfolding.
Clerics and druids have access to all spells. Wizards and elves begin play with four spells – the player may choose two first level spells and one second level spell, but any other spells can only be added to a spell book through game play.
Wizards and elves gain additional spells by finding them in spell books or scrolls to copy to their spell book, or by conducting original research. Spells may not be purchased.
Whether conducting original research or rebuilding a lost spell book, a wizard or elf can build a spell book one spell at a time, at a cost of 1 week of game time and 1,000 gp for each spell level. For instance, if two first level spells and one 2nd level spell are researched, it will take 4 weeks and 4,000 gp. This activity requires complete concentration, and a character doing this work may not engage in any other activity for the duration.
Final word: I've obliterated all spells above level five, an alternative suggested in the Labyrinth Lord rule book. I allow NPC's (such as a lych) to use them, but not characters.