Old School Thief Variant - Adventurer, Ranger, Rogue.

There comes a time in all our lives when we have to 'fix' the Old School Thief.

Considering they're part of the core text of D&D, they needed a lot of modding.

Description: Thief, adventurer, ranger, rogue, ruffian, swashbuckler, scoundrel, hero.

Whatever they call you, your traditional ancestors are still Cugel and the Grey Mouser. But roll high STR/ CON and you're also Conan or Fafhrd without having to multiclass or otherwise bend/break the rules.

You might want this kind of Thief to specify if they're more inclined to the rural, the urban or the dungeon environment, and tweak their abilities accordingly.

XP, Saving Throws, & Attacks: All as Thief.

Hit Dice: Depending on the base system, you start with 2d4 or 2d6 hit points, but gain only 1d4 or 1d6 per level as normal thereafter.

Prime Requisite: Dexterity.

Armour: Any, but as Thief only when you want to do Thief stuff.

Weapons: Any, but you prefer the lighter/smaller hand weapons for special ability reasons.

Alignment Restrictions: None, unless that's important for in your setting/system.

Special Abilities.

Thief Skills: Everything a Thief can normally do, but agree which of either Hear Noise probabilities or boosted percentiles you use before play begins.

If you have a CHA, INT or WIS bonus (highest applies), you can start casting from scrolls that many levels earlier but chances of failure do not change until your levels catch up.

Snipe: You can Backstab using a missile weapon if this is not already allowed.

Dual Wield: When fighting with two weapons, you get +1 to Hit or AC. This also applies to unarmed strikes. You cannot Dual Wield while performing a Backstab.

Choose which bonus to use at the beginning of each combat round, before you roll any dice. 

If you hit, use the higher rolled damage or choose which weapon inflicted the wound (for magic and poisoned weapons, for example)

If you have 18 STR, you can wield a max. d8 and d6 weapon simultaneously; STR 15, 16 or 17, a max. d8 and d4 or d6 and d6; all other STR scores, the max. is d6 and d4.

(This presumes you don't already have Dual Wielding going on anyway)

Cleave: If Fighters get extra attacks vs. <1HD opponents, so do you but only when Dual Wielding.

Surprise: If you are alone or with no more than three other Thieves in leather or no armour, your first surprise attacks count as Backstabs.