Each of the three abilities are used in different circumstances (see saves, below).
Strength (STR): Used for saves requiring physical power, like lifting gates, bending bars, resisting poison, etc.
Dexterity (DEX): Used for saves requiring poise, speed, and reflexes like dodging, climbing, sneaking, balancing, etc.
Willpower (WIL): Used for saves to persuade, deceive, interrogate, intimidate, charm, provoke, manipulate spells, etc.
A save is a roll to avoid bad outcomes from risky choices and circumstances. PCs roll a d20 for an appropriate ability score. If they roll equal to or under that ability score, they pass. Otherwise, they fail. A 1 is always a success, and a 20 is always a failure.
Resting for a few moments and having a drink of water restores lost HP but leaves the party exposed. Ability loss (see Critical Damage) can usually be restored with a week's rest facilitated by a healer or other appropriate source of expertise. Some of these services are free, while magical or more expedient means of recovery may come at a cost.
Deprivation & Fatigue
A PC deprived of a crucial need (such as food or rest) is unable to recover HP or ability scores. Anyone deprived for more than a day adds Fatigue to their inventory, one for each day. Each Fatigue occupies one slot and lasts until they are able to recuperate (such as a full night's rest in a safe spot). PCs can also gain Fatigue by casting spells or through events in the fiction.
Before calculating damage to HP, subtract the target's Armor value from the result of damage rolls. Shields and similar armor provide a bonus defense (e.g. +1 Armor), but only while the item is held or worn.
No one can have more than 3 Armor.
Shields, gauntlets, and helms may provide additional benefits according to their use.
When the PCs encounter an NPC whose reaction to the party is not obvious, the Warden may roll 2d6 and consult the following table:
Enemies must pass a WIL save to avoid fleeing when they take their first casualty and again when they lose half their number. Some groups may use their leader's WIL in place of their own. Lone foes must save when they're reduced to 0 HP. Morale does not affect PCs.
PCs can hire hirelings to aid them in their expeditions. To create a hireling, roll 3d6 for each ability score, then give them 1d6 HP and a simple weapon (d6), then roll on the Character Creation tables to further flesh them out. Hirelings cost between 1-3gp per day, or a share of whatever treasure the party obtains.
Wealth & Treasure
The most common coin is the gold piece (gp), which is equal to 10 silver pieces (sp) and 100 copper pieces (cp).
Treasure is highly valuable, usually bulky, and rarely useful beyond its value. It can be a lure, taking PCs to exotic and even dangerous locations, and is often under the protection of intimidating foes.
Villages, strongholds, and ports of call barter and trade based on the local rarity and value of an item or commodity.