Strength (spell)

This spell changes character strength ability how is is changed depends on character strength from before spell.
 * Strength before casting - Strength after casting
 * 18 and less - 18/50
 * 18/01-18/49 - add 50%(for example 18/02 becomes 18/52)
 * 18/50-18/00 - set to 18/00
 * 19 and more - set to 18/50