Rulebook

The basics

A game of Last Waters is a match: a fixed set of players, its own map, and an ending. It opens as a lobby, runs while the map is contested, and finishes. There is no persistent empire carried between games and nothing to maintain between them.

The map

The world is a graph. Each point on it is a hold — a fortified settlement with ground that yields water, scrap and grain. Each line between two holds is a route: a passage a convoy can survive. Everything else is the Long Waste, which nothing crosses. Units therefore travel only along routes, and two holds that look close together are not neighbours unless a line joins them.

Every player begins holding one hold, with a Bastion standing on it, 10 militia garrisoning it, and 100 water, 100 scrap and 100 grain in store. Everything else on the map starts neutral: unowned, and held by a garrison of between 1 and 8 militia that grows with distance from the nearest starting hold. The far corners of the map are the hardest ground to take and usually the best.

The tick

Nothing happens when a button is pressed. Orders are filed during the day and held. At the tick — the game's resolution moment — every player's orders are read together and resolved against one shared picture of the world as it stood beforehand. Whoever creates a game chooses its cadence: a tick every 6, 12, 24 or 48 hours. The usual choice, and the default, is 24 hours.

Because resolution is simultaneous, nobody sees another faction's orders before committing to their own, and nobody gains anything by being awake at the deadline. Filing nothing is a legal move: holds keep producing, garrisons stay where they stand, and research keeps advancing.

Orders

Seven kinds of order wait for the tick: move, recruit, build, research, and the three alliance orders — propose, accept and break. A player may file as many as their resources allow, and any order can be cancelled at any point before the tick fires. Messages are the exception: they are not orders and do not wait, and are covered under diplomacy.

What happens at the tick

Resolution runs in a fixed sequence of phases. The order is not an implementation detail — it decides games, and it is worth reading once before the first one.

Three consequences fall out of that order:

• Yields are credited before movement, so a hold taken this tick pays its new owner for the first time next tick.
• Recruits arrive before movement, so a faction can raise units at a hold and march that hold's existing garrison out on the same tick — the new units stay, the old ones go.
• Diplomacy and research resolve after the fighting, so a pact signed this tick protects nobody in this tick's battles, and a tech finished this tick takes effect from the next one.

The report

After every tick each player receives a tick report: which of their orders succeeded, which failed and why, what was gained and lost, and what happened in the parts of the world they could see. A report carries only what its reader was entitled to see — see fog of war.

Resources

There are three resources: water, scrap and grain. Each faction holds them in one pool rather than at each hold — every hold's yield goes to the same stockpile, and that stockpile can be spent anywhere on the map. There is nothing to escort and nothing to store: no caravans to route, no cap on how much can be held, and no upkeep. A standing army costs something to raise and nothing to keep.

Yields

Every hold has a fixed yield of each resource per tick, drawn when the map is generated and unchanged for the life of the game. Ground comes in three bands:

Most holds are lean in everything or rich in one thing. A few are barren in all three and are worth taking only for where they sit — a barren hold on the one route into a valley is a gate, not a farm.

Neutral holds yield nothing to anyone. A hold pays only the faction that owned it when the tick began.

What each resource does

• Water is the universal cost. Every unit, every building and every tech asks for it, and several ask for nothing else.
• Scrap is materiel. It dominates the price of fortification and of wreckers, and most of the tech tree wants some.
• Grain feeds the raising of troops. It appears in every unit's cost and in very little else, so a faction rich in grain and poor in scrap can raise soldiers it cannot fortify.

Three buildings add flat yield to the hold they stand on, and four techs multiply what a faction's whole territory produces — see buildings and research.

Units

Three unit types. Attack and defence are each unit's contribution to a fight (see combat); speed is how many routes one may cross in a tick (see movement).

Militia

The backbone. Militia have the best defence of the three types and the lowest cost, and they are the only unit a Bastion can raise, which makes them what every faction starts with and what most garrisons should mostly be. They are slow, and any column carrying them moves at their pace.

Outriders

Reach. At speed 2 outriders cross two routes in a tick where everything else crosses one, which makes them the only unit that can take a distant neutral hold, reinforce a threatened border in time, or arrive somewhere nobody was watching. They attack well and defend poorly: outriders left sitting on captured ground are a cheap prize for whoever comes next.

Wreckers

For walls. Wreckers have the highest attack in the game, and against a hold carrying any fortification — a Bastion, a Palisade, a Muster Hall or a Watch — each of them adds half again on top of it. Their defence of 1 makes them close to worthless standing still. They are brought to break a fortified hold, not to be the garrison that then keeps it.

Raising units

A recruit order names a hold, a unit type and a count. The hold must be owned by the recruiting faction, must carry a building that raises that type, and the whole order must be affordable when the tick resolves — orders filed in the same tick spend from the same stockpile, and one that can no longer be paid for fails rather than partly landing.

A Bastion raises militia only; a Muster Hall raises all three types. Recruits appear before movement resolves, so units raised this tick can defend the hold they were raised in on the tick they were raised.

Buildings

A build order places one building on one owned hold. Buildings are standing by the end of the tick they were ordered in — there is no construction queue and nothing is ever half-built — and the cost leaves the stockpile when the order resolves.

A hold may carry every type at once but never two of the same. Buildings belong to the ground rather than to the owner: a hold that changes hands arrives with its buildings intact. That makes a well-developed hold worth taking, and a well-developed border hold worth garrisoning properly.

The Bastion is a faction's seat and cannot be ordered. Every player begins with exactly one, on their starting hold, and no more are ever built — a faction that loses its Bastion loses it to whoever took the ground.

Reading the effects

• Defence is added to each unit garrisoned at the hold, so a wall is worth more to a large garrison than a small one, and the bonuses of several buildings stack. It also gives wreckers something to break — see combat.
• Sight extends the fog outward from that one hold — see fog of war.
• Research speed stacks across a faction's Archives, up to 3 of them, under an overall ceiling — see research.
• Yield is added to the hold the building stands on, and only while that faction owns it.

Combat

Combat happens at a hold, when forces that are not friendly to one another end the tick in the same place — or when anyone arrives at a neutral hold that still has a garrison on it. There is no fighting on the routes themselves.

Sides

The defender is the hold's owner at the start of the tick, provided they still have units standing there. If the owner marched everyone out, or the ground was neutral and empty, the arriving side that has been in the game longest defends instead, so the fight is settled the same way every time it is replayed. A neutral garrison always defends in its own right. Everyone else attacks, and several attacking sides pool into one force for the assault.

Power

Each side's power is the sum, across every unit type present, of its count multiplied by the stat that matters: attack for the attacking force, defence for the defending one. Two things adjust that sum.

• Fortification is added to each defending unit's own defence before the multiply, not to the total. The same Palisade is therefore worth three times as much to thirty militia as it is to ten, and building one without a garrison to stand behind it achieves very little.
• Siege scales each attacking type's contribution by its own bonus against a fortified hold. Only wreckers carry one, at half again, and only when the defended hold actually has a fortifying building on it.

Losses

Each side takes damage equal to the other side's power, varied by up to 10% at random in either direction. A side's losses are that damage divided by its own power, capped at its whole force, and are spread across its unit types in proportion to how many of each it brought. Both sides lose units in every fight. There is no clean victory, and a battle won at the wrong price is how most positions collapse.

Outcomes

Units that left do not defend

Movement resolves before arrival. A garrison ordered out of a hold has gone from it by the time anyone arrives, whatever else happens that tick — and if the destination was itself emptied, both holds change hands with no fight at all. Emptying a hold in order to attack is the most punished mistake in the game, and it is punished by an opponent who guessed right rather than by the rules. See movement.

Allies and multi-way fights

Two factions are friendly if they hold an active pact, or held one recently enough to still be inside its break cooldown. Friendly forces never fight: they pool into a single force, and their losses are apportioned between them by what each contributed. Friendliness is not transitive — a faction allied to two others who are not allied to each other has two allies who will fight each other over the same ground, and cannot prevent it. Where more than one hostile side survives an assault, they settle the hold between themselves in turn until one is left. See diplomacy.

Research changes the stats this arithmetic reads rather than the arithmetic itself: Outrider Drills raises every outrider's attack, Iron Ranks every unit's defence, Palisade Craft what every Palisade is worth. Because the bonus is added to each unit, it scales with the force carrying it. See research.

Movement

A move order names an origin hold the faction owns, a path of one or more routes, and which units from that hold's garrison are marching. A column may mix types freely.

How far a column goes

A column moves at the pace of its slowest member. Outriders travelling alone cross two routes in a tick; any column carrying militia or wreckers crosses one. Two techs change this. Long Roads gives outriders a third route. Convoy Routes grants an extra route for each hop that ends on ground the faction already holds — so militia under Convoy Routes cross two of their own holds, or one of anybody else's.

Passing through

The holds in the middle of a path are crossed, not visited. They are not captured, nothing is left garrisoning them, and a hostile force standing on one is passed rather than engaged. A convoy crossing the Waste is not obliged to stop for everyone whose ground it drives over. Only the far end of the path is arrived at, and only the far end can be taken.

Everything moves at once

Every move is checked against the world as it stood before the tick, never against a world already changed by somebody else's order. Two columns swapping holds pass each other in the Waste and both arrive. A faction that marches out of a hold while a neighbour marches in loses the hold without a fight, and may well have taken one of theirs in the same instant. Overextension is punished, and it is punished symmetrically.

When an order fails

Orders are re-checked at the tick against the same shared snapshot. One whose origin is no longer owned, whose units are no longer standing there, whose path is broken, or whose path is longer than the column can march, fails with a stated reason and appears in the tick report. Units named by a failed order stay exactly where they were.

Fog of war

What a faction can see is recomputed at the end of every tick, radiating outward along the routes from every hold it owns and every hold an active ally owns. Sight is a fact about territory: expanding the border is how a faction sees further.

Size bands

Two routes out a garrison is described rather than counted:

An empty hold reads as the smallest band, so from two routes away an undefended hold and a thin garrison look the same. Confirming which is which costs a move.

Memory

Memory does not fade. A hold seen once stays on the map as a stale reading, stamped with the tick it was last seen, and it is exactly as wrong as the world has moved since. A stale reading of a hold last seen twenty ticks ago is a historical record, not intelligence.

Seeing further

A Watch adds a route of sight to the hold it stands on. Signaling adds a route to every hold the faction sees from. Watchfires doubles what a Watch is worth. However many of these stack, no hold ever sees more than two routes beyond the base tiers — so the deepest sight in the game is four routes out, with exact counts to three. The ceiling is deliberate: an empire that saw everything would have nothing left to scout for, and scouting is what movement is for.

Allies

An active pact shares sight both ways and at once: an ally's holds are seen in full, and the fog opens around them exactly as it would around ground the faction had taken itself. A proposal shares nothing — it is an offer nobody has taken up. Breaking a pact ends the sharing immediately; the break cooldown restrains armies, not intelligence.

Tick reports obey the same fog. A player reads only the parts of a tick they were entitled to see — though anyone who fought in a battle always reads that battle, whatever they could see beforehand.

Research

A faction researches one tech at a time. Its full resource cost is paid when the research is started; from there it advances by one tick per tick until it completes. A research once started cannot be swapped for another — the faction is committed until it finishes — so the choice matters more than its price.

When a tech starts working

A tech that completes in one tick takes effect from the next. Research resolves after every phase that could have read it, so a bonus finished on the tick of a battle was not in that battle. Prerequisites are the exception: a tech unlocked by one that finished this tick can be started in the same tick, because a prerequisite is a question about what has been learned rather than a bonus being applied.

Speed

Each Archive a faction holds cuts research time by 10%, up to 3 Archives, and Runner Networks cuts a further 20%. The total reduction is capped at 50%, at which point a four-tick tech takes two. Speed is recalculated every tick against what the faction holds now, so an Archive raised in the middle of a research shortens the research already running.

Stacking

Effects on the same stat add together: militia that have both Muster Discipline and Iron Ranks defend at 3 + 1 + 1. Yield multipliers apply to a faction's whole tick total, after any building multiplier has been folded in — so a Growhouse under Grafted Orchards yields double, and Deep Roots then raises the total including it.

Economy techs

Military techs

Logistics techs

Diplomacy techs

Diplomacy

Messages are where the diplomacy actually happens. An alliance is only the part of an agreement the rules can enforce; everything else is what the players say to each other and whether they mean it.

Messages

A message goes to one player or to any group of them, is private to its recipients, and sends immediately rather than waiting for a tick. A faction may send 20 messages an hour, no more than 10 of them to any one player, and each may run to 2,000 characters. Runners' Code doubles the hourly allowance; it does not lift the per-recipient limit, which exists so that one player cannot bury another.

A player may block another player's account from the conversation view. Blocking is silent: a blocked sender is refused without being told who refused them or that a block was involved at all. Blocking is an account-level tool and outlives any single game.

Alliances

An alliance is a pact between two players. One proposes, the other accepts, and both of those are orders that resolve at the tick — an agreement reached in conversation is not a pact until both orders have run. Active pacts are public: every player in the game can see who is allied with whom.

A pact does four things:

• Allied units do not fight each other.
• Allied units share ground: they can garrison the same hold, and they pool their strength in any fight there.
• Each ally's holds are fully visible to the other, and the fog opens around them.
• The pact is on public record until it is broken.

A player may hold 3 active pacts at once by default. Long Councils raises that by one, up to a ceiling of 8 that no amount of research passes.

Alliances are not transitive

A pact is with the player who signed it, not with everyone they have signed with. Two of one faction's allies, unallied to each other, will fight each other over the same hold, and the faction they have in common cannot stop it. A bloc has to be built pact by pact, and every member has to be willing.

Breaking a pact

A break order ends the pact at the tick, and shared sight stops at once. Fighting does not become possible at once. For 2 ticks, counted inclusive of the tick the pact broke in, the former allies still cannot attack each other: a pact broken in tick 5 leaves both untouchable to the other through ticks 5 and 6, and they may fight in tick 7. Emissaries shortens that by a tick for the faction that broke the pact.

Betrayal is therefore always available and never a surprise — the party being left gets a tick or two to move. Leaving one pact for another is likewise a two-tick manoeuvre: within a single tick, proposals are read before breaks, so a pact broken this tick still counts against the cap for a proposal made in the same one.

Victory

There are two ways a game ends.

Elimination

A player who owns no holds at the end of a tick is eliminated. When one player is left standing, that player wins. The check runs after all fighting has resolved, so a faction that loses its last hold and takes another one on the same tick survives — losing everything and gaining something in one instant is not elimination.

The time cap

No game runs past tick 50. If nobody has won by elimination when that tick resolves, the player holding the most holds wins. A tie is settled first by the larger total of water, scrap and grain, and then, if that is level too, in favour of the faction seated earliest in the game. A long game is decided on territory, so a faction that has stopped expanding has started losing.

An ended game stays readable. Its final map and its whole run of tick reports remain available to everyone who played it.

Getting started

A suggested shape for a first game. None of it is a rule, and a game where everyone plays this way is not one anybody remembers.

Take ground early

The neutral holds nearest home are defended by a militiaman or two and will fall to a small force. The further out they sit, the harder they are. Expanding early is nearly always right: a hold taken on tick 3 pays out for the rest of the game, and the same hold taken on tick 30 pays for a fifth of it.

Send enough, and send it once

A force that loses is wasted twice: the units are gone and the hold is still not taken. Roughly twice a neutral garrison's number in militia is comfortable. Attacking is harder than defending — militia attack at 2 and defend at 3, before any wall is counted — so a column that only just matches the garrison it is walking into will not come back.

Never empty a hold to attack

Units that march do not defend the ground they left. Leave a garrison behind, or accept that anyone who guessed right takes the hold for nothing. This is the mistake that decides most first games, on both sides of it.

Build the economy before the army

A Growhouse or a Salvage Yard costs thirty resources and returns five a tick. It has paid for itself inside six ticks and is profit for the rest of the game — and in a fifty-tick game there is a great deal of game after tick six. Put them on holds that are already rich in what they produce, and put them up before anything military.

Raise a Muster Hall before it is needed

A Bastion raises militia and nothing else. The first Muster Hall is what makes outriders and wreckers possible at all, and putting it on the hold that faces a likely opponent saves marching every reinforcement across the whole map afterwards.

Always be researching something

An idle faction is wasting ticks. The three cheap yield techs — Scrapcraft, Deep Roots and Cistern Works — take two ticks each and raise everything the faction produces for the rest of the game. Start with whichever resource the faction's ground already gives most of; multiplying a large number is worth more than multiplying a small one.

Talk to people before tick ten

Alliances are cheap, publicly recorded and slow to escape from, which is exactly what makes them worth having. The break cooldown means an ally cannot turn without giving a tick or two of warning, so an early pact on a quiet border is a genuinely cheap way to buy a safe flank and half a map's worth of sight. Say what is intended and then do it: in a game this small, a reputation is a real asset and is spent only once.

Read the report

Every tick report says which orders failed and why. Most first-game mistakes are written down there on the tick they were made, in plain words, by a game that has no reason to flatter anyone.