Numenera: Ghosts of the Past
Numenera uses a 20-sided dice (1d20) to determine most rolls.
The GM sets a difficulty from 1 to 10 for any given task. You must roll the target number of that task to succeed. The target number is 3x the difficulty score. So a difficulty 1 requires a roll of 3 or higher. A difficulty 4 requires a roll of 12 or higher. As you can see, a difficulty of 7 would be impossible, as it requires a roll of 21 or higher on a d20. Normal humans cannot do these feats.
But you are not normal. That is why your character stats, abilities, and equipment lowers the score of these difficulties, sometimes making them automatic successes.
To lower difficulties, you must have favorable circumstances, bonuses from gear, be trained or specialized in the skill, or some other asset to help, or apply effort from your stat pools.
When a skill is:
Trained…………. reduces by 1 step
Specialized…… reduces by 2 step
Assets: (including equipment, aid from another character, or other circumstances)
reduces by 1 step for each, however cannot stack higher than 2 from assets.
reduces by as many levels of effort applied Character Stats
The GM does not roll dice in this game. When a player attacks, he rolls against the enemy’s difficulty. When he is attacked, he defends against the enemy’s difficulty. Creatures have difficulties of 1 to 10. This number is multiplied by 3 and the result is the target number to attack or defend. Assets, effort, and skills can lower this difficulty.
Damage done is a flat number determined by the weapon type. A spear always does 4 points of damage:
Light weapons: 2 points of damage, but they reduce the difficulty by 1 because they are agile and easy to use. Punches, kicks, clubs, knives, handaxes, rapiers, etc.
Medium weapons: 4 points of damage. Swords, battleaxes, maces, crossbows, spears, etc. Anything that can be used in 1 hand.
Heavy weapons: 6 points of damage, and must use 2 hands to attack with them. Haberds, great hammers, huge swords, etc.
Armor: subtract your armor score from the damage inflicted and take the remainder.
Rarely, an ability or equipment does not decrease a task’s difficulty, but instead increases your roll. Bonuses add together. If the bonuses add up to +3, decrease the difficulty by 1 step, rather than adding to your roll. Therefore, you should never add more than +1 or +2 to a roll.
Special Rolls (Crits)
When you roll a natural 19 AND the roll is a success, you also have a minor effect. In combat, a minor effect deals 3 additional points of damage, or if you prefer, you can knock the foe back, distract him, disarm him, or something similar. Not in combat, a 19 means you perform the task with particular grace and get a minor bonus if it applies.
When you roll a natural 20 AND the roll is a success, you also have a major effect. This can be 4 points of damage or you can choose a dramatic effect, knocking someone down, stunning them, taking an extra action, etc. Out of combat, you do something twice as fast. You can also choose to do a minor effect instead
In combat (and only in combat) a roll of 17 adds 1 point of damage. A roll of 18 adds 2 points of damage. These rolls do not apply effects, only extra damage
Rolling a 1 is always bad. The GM gets to intrude and does not award XP.
Since the GM does not roll, and cannot do things such as do a listen check to see if the enemy heard you, he can choose to “intrude” and basically do anything he wants at any time. When he does this, he must award 2 Experience to the group. 1 XP goes to the player it most directly effects, and the other XP is awarded by that player to another player immediately.
XP is used to advance characters, but may also be expended to reroll any roll.