Task Difficulty Modifier

Task Difficulty Modifier (commonly called TDM) is based on B345 "Task Difficulty" listing "difficulty modifiers". It combines both phrases and serves as a modifier to a skill.

Basic Action Difficulty (BAD) is a more generalized version which covers "all aspects of a particular phase of the adventure" related to enemy planning, security systems, and social connections. BAD should not be applied to combat or chases.

Task Difficulty Modifiers

Classification	Description	modifier	DC	Equivalent
Automatic	Tasks so trivial that waiving the success roll is an option	+10	0	Very Easy
Trivial	Situations where failure is extremely unlikely, and would require incredibly bad luck.	+8 or +9
Very Easy	Tasks where failure is possible, but would require bad luck	+7 or +6
Easy	Most mundane tasks, including rolls made by ordinary people at day-to-day jobs	+4 or +5	5	Easy
Very Favorable	Mildly risky tasks that most people would undertake without hesitation	+3 or +2
Favorable	Tasks that most people would hesitate at, due to the risk, but that a career adventurer would regard as easy.	+1
Average	Most adventuring tasks, and the majority of skill use under stress	no modifier	10	Average
Unfavorable	Stressful tasks that would challenge a novice adventurer, but not an old hand	-1
Very Unfavorable	Stressful tasks that would challenge a professional	-2 or -3	15	Tough
Hard	Tasks so challenging that even an expert will look for alternatives	-4 or -5	20	Challenging
Very Hard	Situations that even the masters might have second thoughts about	-6 or -7	25	Formidable
Dangerous	Tasks at which even the greatest masters expect to fail	-8 or -9	30	Heroic
Impossible	No sane person would attempt such a task	-10	40	Nearly impossible

Modifiers

• Equipment
  • No equipment: -10 for TL skills, -5 otherwise
  • Improvised equipment: -5 for TL skills, -2 otherwise
  • Basic equipment: ±0
    • Basic and above: Missing important tools (-1 per tool); Damaged equipment (-1 to -3)
  • Good-quality equipment (5x basic price): +1
  • Fine-quality equipment (20x basic price): +2
  • Best equipment possible at relevant TL: +TL/2, round down (minimum +2)
• Time Spent
  • Extra Time for bonuses
  • Haste for penalties using less time

Ordinary Working Professionals

"The standard rules are designed for adventurers, not for ordinary working professionals. Professionals make one job roll a month. On a critical failure, something bad happens, with harmful consequences – but not usually as bad as a critical failure during an adventure. (...) With one roll a month, a mage with effective skill 15 or less goes 54 months between mishaps, on the average; one with effective skill 16 or better could go 216 months (or 18 years)."

This explains why worlds with common spell casting aren't devastated demon infested nightmarish Hell Worlds.

Threads

• 2006 query thread
  • Kromm: We don't use "TDM" to mean anything in GURPS, although some people might use that abbreviation.
• 2007 without explanation

See also

• Attacking Inanimate Objects