House Rule: Casting Unprepared

This is a house rule for Basic (Moldvay) D&D and Labyrinth Lord.

House Rule: Casting Unprepared

Upon reaching 3rd level, a magic-user or elf may attempt to cast a spell they've previously learned (i.e., have transcribed into their spell book) without proper preparation (i.e., not having memorized it). There is risk in so doing, for magic spells are intricate, and even a small mistake while casting might produce a grave complication. The more powerful the spell, the greater the risk.

To cast a spell without proper preparation, roll 2D6, subtract the level of the spell, and consult the following chart:

Net | Outcome

--------------------------------------------------------

10+ | The spell is cast successfully with no 
      complications, as if it had been memorized

7-9 | The spell is cast successfully, but there is 

      a minor complication

4-6 | The spell fails, and there is a minor complication 

2-3 | The spell fails, and there is a major complication

 1- | The spell fails, and the caster must save versus 
      magic; if the save succeeds, caster collapses and 
      will be unconscious for 1d4 round; if the save 
      fails, the caster dies

If a natural 12 is rolled *and* the net result is 10+, the spell's effect is doubled, as the caster unknowingly improved the spell by mistake.

At each 3rd level beyond level 3 (e.g., levels 6, 9, 12, etc.), the caster gets a cumulative +1 to the casting unprepared roll above.

Example

Singe is a 6th-level magic-user. In the previous round, Singe cast her last memorized Fireball spell. This round, she decides to cast the spell without proper preparation. Her player rolls 2D6 for a result of 8, subtracts 3 for the spell's level, and adds 1 for her bonus (because she is 6th level), for a net result of 6. Singe fails to cast the Fireball spell, and there is a minor complication. Her player suggests to the DM that the complication be Singe's hair is set on fire (there is history here, as her name suggests) and she loses the next round extinguishing the flames. The DM agrees.