WWN comes out of creating a fantasy version of Stars Without Number, which is itself something of a D&D / Traveller hybrid. So skills are typically 2d6 + attribute + modifier, whereas attacks and saving throws are d20 + attribute + modifier. The standard method in the game is that Attributes are rolled 3d6 in order and then bump one to 14. There is also a standard array without the 14 bump. Attribute modifiers are much flatter: 8-13 (no modifier), 14-17 (+1), and 18 (+2).
WWN Character Summary
Backgrounds and Skills: Players can choose or roll for a Background. Backgrounds provide one free skill. From there, players can choose whether to pick the two quick skills
OR they can choose to roll
three times for the chance to gain a random skill or attribute (either mental/physical). A character's proficiency in a skill starts at -1. You are trained in a skill at +0. And proficiency in a skill caps at +4. Remember that this is 2d6 + Attribute + Skill Modifier, with Skill Check difficulties of 14+ being only possible by true masters.
Class: Players then choose their class. There are three standard classes: Expert, Mage, Warrior. The Expert is best at skills. The Mage is best at magic. The Warrior is best at combat. Each class gets one or two special abilities as part of the class. For example, the Warrior gains
Veteran's Luck, which lets them once per scene turn a missed attack they made into a hit or turn a hit against them into a miss. Additionally there is the Adventurer class, which has rules for the multiclass combos: Warrior/Mage, Mage/Expert, and Expert/Warrior. It's typically in the Adventurer that the other specialized partial classes operate: e.g., Bard (Expert partial class) can be a Bard/Expert, Bard/Warrior, or Bard/Mage. But you can also combine partial classes: e.g., Bard/Psychic, Bard/Duelist, Bard/Priest, etc.
Foci: Players then choose a Focus, which are much like feats. Foci have two tiers, so you can potentially take the same Focus twice and gain an additional benefit. Since a mage's choice of Arcane Tradition provides them access to various non-spell arcane arts, Warriors and Experts (as well as partial Warriors or Experts) gain a bonus foci. Warriors gain a free combat foci and Experts gain a free non-combat focus.
Weapons & Shock: Some weapons have a Shock value. Shock is damage on a miss that is inflicted if the target has an AC less than or equal to the value. For example, a Long Sword has 2/AC 13 for Shock. This means that a Long Sword will inflict 2 + Str/Dex damage against a target on a miss if that target has an AC of 13 or less. This is meant to keep combat (a) deadly and (b) quick so there is not just round after round of misses. Ranged weapons do not have Shock. So this gives more risk/reward with melee weapons.
Race/Ancestry: I have not talked about ancestry yet. Worlds Without Number takes place in a Latter Earth setting where humans are the presumed norm. There are, however, rules for creating more standard fare tabletop fantasy demihumans with some sample ones, including gnomes.

If a player picks one of these demihuman options, then they give up their free starting focus. I will also note that WWN also has its own version of elves and dwarves that fit its setting.