Not everyone like World of Darkness' dicepool system, so I present modified single D10 mechanics.
Attribute + Skill Rolls
In oWoD you roll D10's equal to your attribute + skill and count successes from the dice what are under difficulty. Let's change this.
Total your character's Attribute + Skill. Modify difficulty:
Difficulty 4 +2 to attr+skill
Difficulty 5 +1 to attr+skill
Difficulty 6 no changes
Difficulty 7 -1 to attr+skill
Difficulty 8 -2 to attr+skill
Difficulty 9 -3 to attr+skill
Difficulty 10 -4 to attr+skill
If after modified difficulty to attribute + skill value result is 0 or negative, concider it as an "1". If after modification attr+skill is over 10, result "10" is automatic failure and possible botch.
Converting Dice Pool To Single Die:
To Success, Fail, Multiple Successes And Botch
To success roll result must be under attr+skill (after difficulty modifier).
Fail occurs when roll is higher than attr+skill (after difficulty modifier) or automatic failure with result "10".
Multiple successes are equal to die result -3. If you roll exact same as attr+skill (after difficulty modifiers) roll again and add second result's possible multiple successes to previous successes.
To botch roll +5 higher than your attr+skill (after difficulty modifier). If attr+skill (after difficulty modifier) is over 10, roll two again after result "10". If second roll is a failure, roll is botched.
Basically follow To success, fail, multiple successes and botch rules converting dice pool to single die.
To success in damage roll, roll below weapon damage + possible str bonus. Add +1 for every 2 previous to hit roll successes to weapon damage + possible str bonus as every 2 dots in strength is +1 to damage target number.
Damage equals to die result under the target number. If die roll is above, no damage is dealt.
Soaking damage with stamina: Add +3 to stamina and Roll D10 against stamina value to soak equal number of damage. No modifications are made to stamina or soak roll.
Vampire character tries to persuade guards to let him in. Use character's Manipulation 3 + Subterfuge 4 to get a target number of 7. Guards are hard to persuade, thus difficulty is 7 so decrease 1 from target number 6. Roll D10 and try to get under 6 to success.
With results 1, 2, 3, 4 player scores 1 success.
With result 5 player scores 2 successes.
With result 6 player scores 3 successes and rolls again for possible extra successes.
With results 7, 8, 9 character fails.
With result 10 roll again. If second roll is failure, roll is botched.
After rolling for attack roll with a knife (damage 3) character gained 3 successes. From successes character gains +1 to damage, 3 damage from knife and 1 from strength (3). Total target number for damage is 5. Roll D10 to determine damage. Rolls 1, 2, 3, 4 and 5 equal to it's value of damage, rolls 6, 7 ,8, 9 and 10 deal no damage.
With roll 5 roll again and add possible second rolls damage to previous.
Vampire is shot with a shotgun. Attack roll gained no extra successes and shotguns damage is 8. Roll D10. Results 1, 2, 3, 4, 5, 6, 7 and 8 deal damage equal to die result, 9 and 10 deal no damage. Roll 8 again for possible more damage successes.
Character suffers 6 damage with stamina value of 3 +3 to soak. Player rolls D10 and gets result "2". 2 points of damage are soaked. With results 1, 2, 3, 4, 5 and 6 equal number of damage would have been soaked.