CB-WP-0008-T01: bots — the kernel's first non-scenario consumer
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A Policy trait, a seeded random policy and a greedy one with a stated
heuristic, a legal-command generator that filters candidates through
validate, and a driver that runs a 3-player all-bot game to GameEnded.
Same-seed runs are hash-identical (K8), and a different policy seed
produces a different game — without that second assertion the first is
satisfied by a bot that ignores its RNG.

Every failure is loud, because the one a bot driver must not have is the
silent one: no legal move, passing where an action is required, an
out-of-range index (not clamped), a rejected command, and a stall guard.

What the second consumer found, none of it fixed here:
- GR-A13 admits SOLVE against an already-claimed Problem and resolution
  then does nothing — the action is silently wasted. The policy avoids
  it; the rule is left for a ruling.
- The 3-player standard fixture cannot reach GR-E01's threshold of 7:
  three Problems valued 1,2,3 cap the total at 6. No scenario noticed
  because none plays to scoring.
- K13's Project trait still has zero implementors. T02 is its first.

Mutation-checked by hand. The first mutation was a no-op and survived;
removing the Resolve call outright turned three tests red for the stated
reason. Third instance of the weak-mutation class.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
This commit is contained in:
tegwick 2026-08-01 14:29:45 +02:00
parent be2d7a3e5a
commit 6197677126
4 changed files with 926 additions and 2 deletions

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games/ground/src/bot.rs Normal file
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//! Bots — the kernel's first non-scenario consumer (CB-WP-0008 T01).
//!
//! Everything here drives `GroundState` through the ordinary
//! `Aggregate::validate` → `fold` path. Nothing in this module reaches
//! into state to mutate it: a bot that did would prove nothing about the
//! kernel, which is the whole reason INTENT wants a *second* consumer.
//!
//! **Stated limit on [`legal_commands`].** It is complete only up to the
//! candidate shapes it enumerates. Every candidate it yields is legal —
//! each one is filtered through `validate` — but a command shape this
//! function forgets to construct is invisible, and nothing here detects
//! that. Under-generation is the failure mode; it would show up as a bot
//! that never uses a rule, not as an error.
use crate::{
Action, DarvoTarget, GroundChoice, GroundCommand, GroundMode, GroundState, Relation, RoundStep,
Selection, SupportResponse,
};
use cb_kernel::{Actor, Aggregate, ChaChaRng, KernelRng, PlayerId, Rejection, Seed};
/// A seat's decision when offered the legal commands available to it.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Choice {
/// Index into the offered slice.
Command(usize),
/// Decline to act. Legal only where the driver says it is.
Pass,
}
/// How one seat decides. Implementors see the whole state — bots are not
/// the place to enforce hidden information; that is K13's projection, and
/// [`crate::bot`] deliberately does not pretend otherwise.
pub trait Policy {
fn name(&self) -> &'static str;
/// Pick one of `legal`, or [`Choice::Pass`] when `may_pass`.
///
/// `legal` is never empty when this is called: the driver treats an
/// empty legal set at an obligatory point as [`BotError::NoLegalMove`]
/// rather than asking a policy to invent a move.
fn choose(
&mut self,
state: &GroundState,
seat: PlayerId,
legal: &[GroundCommand],
may_pass: bool,
) -> Choice;
}
/// Every way a bot game can fail. All of them are **loud**: the failure a
/// bot driver must never have is the silent one, where a stalled game is
/// indistinguishable from a finished one.
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum BotError {
/// A seat had to act and had nothing legal to do.
NoLegalMove {
seat: PlayerId,
round: u8,
step: RoundStep,
},
/// A policy passed where passing is not allowed.
PassedWhenObligatory {
seat: PlayerId,
round: u8,
step: RoundStep,
},
/// A policy returned an index outside the offered slice. Not clamped:
/// clamping would turn a broken policy into a quietly playing one.
IllegalChoice {
seat: PlayerId,
index: usize,
offered: usize,
},
/// A command the driver generated was rejected. Since generation is
/// validate-filtered, this means state moved underneath it.
Rejected {
seat: Option<PlayerId>,
command: String,
rejection: Rejection,
},
/// The game did not progress. A bot that loops forever looks like a
/// bot that is working; this is the guard that makes it look broken.
Stalled { round: u8, detail: String },
/// Fewer policies than seats.
NoPolicy { seat: PlayerId },
}
impl core::fmt::Display for BotError {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
match self {
BotError::NoLegalMove { seat, round, step } => write!(
f,
"player {seat} has no legal command in round {round} {step:?}"
),
BotError::PassedWhenObligatory { seat, round, step } => write!(
f,
"player {seat} passed in round {round} {step:?}, where an action is required"
),
BotError::IllegalChoice {
seat,
index,
offered,
} => write!(
f,
"player {seat}'s policy chose index {index} of {offered} offered commands"
),
BotError::Rejected {
seat,
command,
rejection,
} => write!(f, "{seat:?} issuing {command} was rejected: {rejection}"),
BotError::Stalled { round, detail } => {
write!(f, "game stalled in round {round}: {detail}")
}
BotError::NoPolicy { seat } => write!(f, "no policy for seat {seat}"),
}
}
}
/// What a completed bot game produced.
#[derive(Debug, Clone)]
pub struct BotGame {
pub state: GroundState,
/// Every event, in order — the log a replay bundle would carry.
pub events: Vec<crate::GroundEvent>,
/// Commands accepted, player and system alike.
pub commands: usize,
pub rounds: u8,
}
// ------------------------------------------------------------ generation
/// Every legal command `seat` may issue right now, in canonical order.
///
/// Candidates are constructed then filtered through `validate`, so the
/// game rules stay in one place. See the module note for what this
/// cannot tell you.
pub fn legal_commands(state: &GroundState, seat: PlayerId) -> Vec<GroundCommand> {
let seats: Vec<PlayerId> = state.players.keys().copied().collect();
let problems: Vec<u32> = state.problems.keys().copied().collect();
let mut candidates: Vec<GroundCommand> = Vec::new();
match state.step {
RoundStep::Select => {
for action in [
Action::Investigate,
Action::Solve,
Action::Support,
Action::Attack,
Action::Ground,
] {
match action {
Action::Investigate | Action::Solve => {
for problem in &problems {
candidates.push(GroundCommand::SelectAction {
action,
target: None,
problem: Some(*problem),
});
}
}
Action::Support | Action::Attack => {
for other in &seats {
candidates.push(GroundCommand::SelectAction {
action,
target: Some(*other),
problem: None,
});
}
}
Action::Ground => candidates.push(GroundCommand::SelectAction {
action,
target: None,
problem: None,
}),
}
}
candidates.push(GroundCommand::SpendFreedom);
}
RoundStep::Reveal => {
candidates.push(GroundCommand::ChooseGroundMode {
mode: GroundMode::Gr,
choice: None,
});
for problem in &problems {
for choice in [
GroundChoice::RestoreProblem { problem: *problem },
GroundChoice::ProtectProblem { problem: *problem },
] {
candidates.push(GroundCommand::ChooseGroundMode {
mode: GroundMode::Ou,
choice: Some(choice),
});
}
}
for other in &seats {
candidates.push(GroundCommand::ChooseGroundMode {
mode: GroundMode::Ou,
choice: Some(GroundChoice::CancelAttack { attacker: *other }),
});
for choice in [
GroundChoice::RemoveBlame { owner: *other },
GroundChoice::BreakRelation { with: *other },
] {
candidates.push(GroundCommand::ChooseGroundMode {
mode: GroundMode::Nd,
choice: Some(choice),
});
}
}
candidates.push(GroundCommand::ChooseGroundMode {
mode: GroundMode::Nd,
choice: Some(GroundChoice::RejectReverse),
});
for response in [
SupportResponse::AcceptBond,
SupportResponse::DeclineBond,
SupportResponse::FlipToBond,
SupportResponse::BreakRivalry,
] {
candidates.push(GroundCommand::RespondToSupport { response });
}
for problem in &problems {
candidates.push(GroundCommand::ChooseDarvoTarget {
target: DarvoTarget {
problem: Some(*problem),
player: None,
},
});
}
for other in &seats {
candidates.push(GroundCommand::ChooseDarvoTarget {
target: DarvoTarget {
problem: None,
player: Some(*other),
},
});
}
}
// GR-R06/R08: system-driven; a seat has nothing to issue.
RoundStep::Resolve | RoundStep::End => {}
}
candidates
.into_iter()
.filter(|cmd| state.validate(Actor::Player(seat), cmd).is_ok())
.collect()
}
// --------------------------------------------------------------- policies
/// Uniform over the legal commands, from a seeded kernel RNG so a bot
/// game stays deterministic and replayable (K8).
pub struct RandomPolicy {
rng: ChaChaRng,
/// Probability, in sixteenths, of taking an optional action rather
/// than passing. Fixed rather than tunable: a knob here would be a
/// parameter nobody has a second use for.
act_in_16: u32,
}
impl RandomPolicy {
pub fn new(seed: u64) -> Self {
Self {
rng: ChaChaRng::from_seed(Seed(seed)),
act_in_16: 12,
}
}
}
impl Policy for RandomPolicy {
fn name(&self) -> &'static str {
"random"
}
fn choose(
&mut self,
_state: &GroundState,
_seat: PlayerId,
legal: &[GroundCommand],
may_pass: bool,
) -> Choice {
if may_pass && self.rng.draw(16) >= self.act_in_16 {
return Choice::Pass;
}
Choice::Command(self.rng.draw(legal.len() as u32) as usize)
}
}
/// A stated heuristic, in priority order:
///
/// 1. **Get out from under the stress gate.** At Stress ≥ 4 only ATTACK
/// and GROUND are selectable (GR-R03), so GROUND—GR (2 Stress) is
/// worth more than anything else on the board.
/// 2. **SOLVE** a face-up Problem — the only action that adds to the
/// shared total the outcome is scored against (GR-E01).
/// 3. **INVESTIGATE** — turns a hidden Problem face up, which is what
/// makes a later SOLVE possible.
/// 4. **SUPPORT** — Bonds are the cheapest relationship and feed GR-E04.
/// 5. **GROUND**, then **ATTACK** last: attacking raises another seat's
/// Stress, which under SHARED GROUND scoring costs the group.
///
/// Deterministic by construction: ties break toward the earlier candidate
/// in canonical order, so two runs of a greedy game are identical without
/// needing a seed.
#[derive(Debug, Default, Clone, Copy)]
pub struct GreedyPolicy;
impl GreedyPolicy {
fn rank(state: &GroundState, seat: PlayerId, cmd: &GroundCommand) -> i32 {
let gated = state
.players
.get(&seat)
.is_some_and(|p| p.stress >= 4 && !p.freedom_gate_lifted);
match cmd {
GroundCommand::SelectAction {
action, problem, ..
} => match action {
Action::Ground if gated => 100,
// GR-A13 admits SOLVE against an already-claimed Problem
// (it names only "face-up, non-Denied"), and resolution
// then does nothing — the action is silently wasted. The
// policy avoids it; the *rule* is left alone, and the gap
// is recorded rather than patched here.
Action::Solve
if problem
.and_then(|p| state.problems.get(&p))
.is_some_and(|p| p.claimed_by.is_some()) =>
{
5
}
Action::Solve => 90,
Action::Investigate => 80,
Action::Support => 70,
Action::Ground => 60,
Action::Attack => 10,
},
// Only worth spending when the gate is actually biting.
GroundCommand::SpendFreedom => {
if gated {
95
} else {
0
}
}
GroundCommand::ChooseGroundMode { mode, choice } => match (mode, choice) {
// GR-A10: the only mode that lowers our own Stress.
(GroundMode::Gr, _) => 90,
(_, Some(GroundChoice::RestoreProblem { .. })) => 80,
(_, Some(GroundChoice::CancelAttack { .. })) => 75,
(_, Some(GroundChoice::ProtectProblem { .. })) => 70,
(_, Some(GroundChoice::RemoveBlame { .. })) => 65,
_ => 40,
},
// GR-L02/A05: take the Bond wherever one is on offer.
GroundCommand::RespondToSupport { response } => match response {
SupportResponse::AcceptBond | SupportResponse::FlipToBond => 90,
SupportResponse::BreakRivalry => 50,
SupportResponse::DeclineBond => 10,
},
GroundCommand::ChooseDarvoTarget { .. } => 50,
GroundCommand::Reveal | GroundCommand::Resolve | GroundCommand::EndRound => -1,
}
}
}
impl Policy for GreedyPolicy {
fn name(&self) -> &'static str {
"greedy"
}
fn choose(
&mut self,
state: &GroundState,
seat: PlayerId,
legal: &[GroundCommand],
_may_pass: bool,
) -> Choice {
let mut best = 0usize;
let mut best_rank = i32::MIN;
for (i, cmd) in legal.iter().enumerate() {
let rank = Self::rank(state, seat, cmd);
if rank > best_rank {
best_rank = rank;
best = i;
}
}
Choice::Command(best)
}
}
// ----------------------------------------------------------------- driver
/// Rounds the driver will run before declaring a stall. GR-R09 ends the
/// game after five; anything past that is a defect, not a long game.
const MAX_ROUNDS: u8 = 20;
/// Attempts a single seat gets within one step. Bounded so a policy that
/// keeps choosing non-advancing commands fails instead of spinning.
const MAX_ATTEMPTS: usize = 8;
/// Drive `state` to `GameEnded` with one policy per seat.
///
/// Seats are matched to `policies` by index: `PlayerId(n)` gets
/// `policies[n]`.
pub fn play(mut state: GroundState, policies: &mut [Box<dyn Policy>]) -> Result<BotGame, BotError> {
let mut events = Vec::new();
let mut commands = 0usize;
let seats: Vec<PlayerId> = state.players.keys().copied().collect();
for seat in &seats {
if policies.get(seat.0 as usize).is_none() {
return Err(BotError::NoPolicy { seat: *seat });
}
}
let mut rounds = 0u8;
while state.outcome.is_none() {
rounds += 1;
if rounds > MAX_ROUNDS {
return Err(BotError::Stalled {
round: rounds,
detail: format!("no outcome after {MAX_ROUNDS} rounds"),
});
}
let round = state.round;
// GR-R02 — Select. Every seat must end this step with a selection.
for seat in &seats {
let mut attempts = 0;
while !state.selections.contains_key(seat) {
attempts += 1;
if attempts > MAX_ATTEMPTS {
return Err(BotError::Stalled {
round,
detail: format!("player {seat} never selected an action"),
});
}
step_seat(
&mut state,
&mut events,
&mut commands,
policies,
*seat,
round,
false,
)?;
}
}
// Positive control: the driver must have done the work it claims.
if state.selections.len() != state.players.len() {
return Err(BotError::Stalled {
round,
detail: format!(
"Select ended with {} of {} selections",
state.selections.len(),
state.players.len()
),
});
}
apply(
&mut state,
&mut events,
&mut commands,
Actor::System,
&GroundCommand::Reveal,
)?;
// GR-R05 — after Reveal: modes are obligatory for a seat that
// revealed GROUND; Support responses and DARVO targets are not.
for seat in &seats {
let mut attempts = 0;
loop {
attempts += 1;
if attempts > MAX_ATTEMPTS {
return Err(BotError::Stalled {
round,
detail: format!("player {seat} kept acting after Reveal"),
});
}
let obligatory = state
.selections
.get(seat)
.is_some_and(|s| s.action == Action::Ground)
&& !state.ground_modes.contains_key(seat);
if !obligatory && legal_commands(&state, *seat).is_empty() {
break;
}
if !step_seat(
&mut state,
&mut events,
&mut commands,
policies,
*seat,
round,
!obligatory,
)? {
break;
}
}
}
apply(
&mut state,
&mut events,
&mut commands,
Actor::System,
&GroundCommand::Resolve,
)?;
apply(
&mut state,
&mut events,
&mut commands,
Actor::System,
&GroundCommand::EndRound,
)?;
}
Ok(BotGame {
state,
events,
commands,
rounds,
})
}
/// Offer one seat its legal commands and apply what the policy picks.
/// `Ok(false)` means the seat passed.
fn step_seat(
state: &mut GroundState,
events: &mut Vec<crate::GroundEvent>,
commands: &mut usize,
policies: &mut [Box<dyn Policy>],
seat: PlayerId,
round: u8,
may_pass: bool,
) -> Result<bool, BotError> {
let legal = legal_commands(state, seat);
if legal.is_empty() {
if may_pass {
return Ok(false);
}
return Err(BotError::NoLegalMove {
seat,
round,
step: state.step,
});
}
let policy = policies
.get_mut(seat.0 as usize)
.ok_or(BotError::NoPolicy { seat })?;
match policy.choose(state, seat, &legal, may_pass) {
Choice::Pass if may_pass => Ok(false),
Choice::Pass => Err(BotError::PassedWhenObligatory {
seat,
round,
step: state.step,
}),
Choice::Command(i) => {
let cmd = legal.get(i).ok_or(BotError::IllegalChoice {
seat,
index: i,
offered: legal.len(),
})?;
apply(state, events, commands, Actor::Player(seat), cmd)?;
Ok(true)
}
}
}
fn apply(
state: &mut GroundState,
events: &mut Vec<crate::GroundEvent>,
commands: &mut usize,
actor: Actor,
cmd: &GroundCommand,
) -> Result<(), BotError> {
let produced = state
.validate(actor, cmd)
.map_err(|rejection| BotError::Rejected {
seat: match actor {
Actor::Player(p) => Some(p),
Actor::System => None,
},
command: format!("{cmd:?}"),
rejection,
})?;
for event in &produced {
state.fold(event);
}
events.extend(produced);
*commands += 1;
Ok(())
}
/// The selection a seat made this round, for callers that want to report
/// a game rather than only run one.
pub fn selection_of(state: &GroundState, seat: PlayerId) -> Option<Selection> {
state.selections.get(&seat).copied()
}
/// Relation between two seats, for the same reason.
pub fn relation_of(state: &GroundState, a: PlayerId, b: PlayerId) -> Option<Relation> {
state.relations.get(&crate::Pair::new(a, b)).copied()
}
#[cfg(all(test, feature = "scenarios"))]
mod tests {
use super::*;
use cb_events::state_hash_hex;
use cb_game_runtime::{ScenarioGame, Setup};
fn setup(players: u8, seed: u64) -> GroundState {
GroundState::setup(
&Setup {
players,
preset: format!("standard-{players}p"),
patch: Default::default(),
},
seed,
)
.expect("preset")
}
fn policies(kind: &str, n: u8, seed: u64) -> Vec<Box<dyn Policy>> {
(0..n)
.map(|i| -> Box<dyn Policy> {
match kind {
"greedy" => Box::new(GreedyPolicy),
_ => Box::new(RandomPolicy::new(seed + u64::from(i))),
}
})
.collect()
}
/// Acceptance, first half: a 3-player all-bot game reaches GR-R09's
/// end with every command legal (nothing was rejected — `play`
/// returns `Err` on the first rejection).
#[test]
fn three_player_all_bot_game_reaches_game_ended() {
for kind in ["random", "greedy"] {
let game = play(setup(3, 42), &mut policies(kind, 3, 42))
.unwrap_or_else(|e| panic!("{kind} bots: {e}"));
let outcome = game.state.outcome.as_ref().expect("GR-R09 outcome");
assert_eq!(game.state.round, 5, "{kind}: GR-R09 runs five rounds");
assert!(
game.events
.iter()
.any(|e| matches!(e, crate::GroundEvent::GameEnded { .. })),
"{kind}: GameEnded must be in the log"
);
// Positive control: a driver that did nothing would still see
// an outcome if the state arrived scored, so assert the work.
assert!(
game.commands > 3 * 5,
"{kind}: only {} commands for a five-round game",
game.commands
);
assert!(outcome.threshold > 0);
}
}
/// Acceptance, second half (K8): same seed, identical state hash.
#[test]
fn same_seed_bot_games_are_hash_identical() {
let a = play(setup(3, 7), &mut policies("random", 3, 7)).expect("run a");
let b = play(setup(3, 7), &mut policies("random", 3, 7)).expect("run b");
assert_eq!(
state_hash_hex(&a.state),
state_hash_hex(&b.state),
"same-seed bot games must be hash-identical"
);
assert_eq!(a.events.len(), b.events.len());
// And the seed must matter, or the equality above is vacuous —
// two runs of a bot that ignores its RNG are also identical.
let c = play(setup(3, 7), &mut policies("random", 3, 999)).expect("run c");
assert_ne!(
state_hash_hex(&a.state),
state_hash_hex(&c.state),
"different policy seeds must produce a different game"
);
}
/// The positive control the workplan asks for: no legal move must be
/// loud. A seat the game does not contain has no legal command, and
/// the driver must say so rather than skip it.
#[test]
fn a_seat_with_no_legal_move_fails_loudly() {
let mut state = setup(3, 1);
let ghost = PlayerId(9);
assert!(legal_commands(&state, ghost).is_empty());
let mut ps = policies("greedy", 10, 0);
let err = step_seat(
&mut state,
&mut Vec::new(),
&mut 0,
&mut ps,
ghost,
1,
false,
)
.expect_err("a seat with nothing legal must fail");
assert!(matches!(err, BotError::NoLegalMove { seat, .. } if seat == ghost));
}
/// A policy that passes where it may not is a defect, not a turn.
#[test]
fn passing_when_obligatory_fails_loudly() {
struct Passer;
impl Policy for Passer {
fn name(&self) -> &'static str {
"passer"
}
fn choose(
&mut self,
_: &GroundState,
_: PlayerId,
_: &[GroundCommand],
_: bool,
) -> Choice {
Choice::Pass
}
}
let mut ps: Vec<Box<dyn Policy>> = (0..3)
.map(|_| Box::new(Passer) as Box<dyn Policy>)
.collect();
let err = play(setup(3, 3), &mut ps).expect_err("a passing bot must not finish a game");
assert!(
matches!(err, BotError::PassedWhenObligatory { .. }),
"got {err}"
);
}
/// An out-of-range index is not clamped to a legal move.
#[test]
fn an_out_of_range_choice_fails_loudly() {
struct Wild;
impl Policy for Wild {
fn name(&self) -> &'static str {
"wild"
}
fn choose(
&mut self,
_: &GroundState,
_: PlayerId,
legal: &[GroundCommand],
_: bool,
) -> Choice {
Choice::Command(legal.len())
}
}
let mut ps: Vec<Box<dyn Policy>> =
(0..3).map(|_| Box::new(Wild) as Box<dyn Policy>).collect();
let err = play(setup(3, 3), &mut ps).expect_err("an out-of-range index must fail");
assert!(matches!(err, BotError::IllegalChoice { .. }), "got {err}");
}
/// Every command a bot issues goes through `validate`. This asserts
/// the generator agrees with the kernel rather than trusting it.
#[test]
fn every_generated_command_validates() {
let state = setup(3, 11);
let mut total = 0;
for seat in state.players.keys().copied() {
let legal = legal_commands(&state, seat);
assert!(!legal.is_empty(), "seat {seat} has no opening move");
for cmd in &legal {
assert!(
state.validate(Actor::Player(seat), cmd).is_ok(),
"generated {cmd:?} is not legal for {seat}"
);
}
total += legal.len();
}
assert!(
total > 10,
"only {total} legal opening commands across 3 seats"
);
}
/// The greedy heuristic must actually be a heuristic — a policy that
/// ranked everything equally would pick index 0 and still finish.
#[test]
fn greedy_prefers_solve_over_attack() {
let state = setup(3, 5);
let seat = PlayerId(0);
let legal = legal_commands(&state, seat);
let mut p = GreedyPolicy;
let Choice::Command(i) = p.choose(&state, seat, &legal, false) else {
panic!("greedy never passes");
};
match &legal[i] {
GroundCommand::SelectAction { action, .. } => assert!(
matches!(action, Action::Solve | Action::Investigate),
"greedy opened with {action:?}"
),
other => panic!("greedy opened with {other:?}"),
}
}
/// HDN control: a bot game that "finishes" without touching the board
/// is the failure this project keeps finding. Assert the game moved.
#[test]
fn a_bot_game_does_substantive_work() {
for kind in ["random", "greedy"] {
let g = play(setup(3, 42), &mut policies(kind, 3, 42)).expect("game");
let mut counts: std::collections::BTreeMap<String, usize> =
std::collections::BTreeMap::new();
for e in &g.events {
let text = format!("{e:?}");
let kind = text.split([' ', '{']).next().unwrap_or("?").to_string();
*counts.entry(kind).or_default() += 1;
}
println!(
"{kind}: cmds={} events={} {counts:?}",
g.commands,
g.events.len()
);
println!(" outcome {:?}", g.state.outcome);
// Every seat selected in every round (GR-R02 × GR-R09).
assert_eq!(
counts.get("ActionSelected").copied().unwrap_or(0),
3 * 5,
"{kind}: a five-round three-player game has fifteen selections"
);
// And resolution actually did something with them. A driver
// that selected, revealed and ended without resolving would
// pass every assertion above this line.
let board_moved: usize = [
"ProblemClaimed",
"ProblemRevealed",
"RelationFormed",
"StressSet",
"SolutionDrawn",
]
.iter()
.filter_map(|k| counts.get(*k))
.sum();
assert!(
board_moved >= 4,
"{kind}: only {board_moved} board-changing events in a whole game"
);
}
}
}

View file

@ -2,6 +2,12 @@
//! GameKernel K15K16). Every rule realized here names its GR-id in a doc
//! comment, giving a greppable rule→code→scenario chain.
/// Bots (CB-WP-0008 T01) — the kernel's first non-scenario consumer.
/// Deliberately **not** gated on `scenarios`: a bot needs only the
/// aggregate. That its tests do need `scenarios` is a real seam — setup
/// presets currently live behind that feature (see `bot.rs`).
pub mod bot;
#[cfg(feature = "scenarios")]
use cb_game_runtime::{parse_actor, CommandStep, ScenarioGame, Setup};
use cb_kernel::{Actor, Aggregate, ChaChaRng, KernelRng, PlayerId, Rejection, Seed};

View file

@ -0,0 +1,64 @@
# 2026-08-01 — CB-WP-0008 delivery notes
Kept out of the workplan file so it stays loadable (`loop-lint`).
## T01 — bots
`games/ground/src/bot.rs`, 8 tests. `Policy` + `RandomPolicy` (seeded
`ChaChaRng`) + `GreedyPolicy` (stated heuristic, deterministic), a
`legal_commands` generator that filters candidates through `validate`, and
a driver that reaches `GameEnded`.
Measured, 3-player, seed 42, both policies to GR-R09's fifth round:
| policy | commands | events | claimed | total vs threshold |
|---|---|---|---|---|
| random | 36 | 81 | 1 | 2 / 7 |
| greedy | 30 | 51 | 2 | 3 / 7 |
**The module is not gated on `scenarios`; its tests are.** A bot needs
only the aggregate, but the setup presets live behind that feature. That
is a real seam and it is left visible rather than papered over with a
feature the bot does not need.
### What the second consumer found
INTENT's second-use rule is why T01 was worth doing before the CLI. Three
findings, none of them fixed here, because fixing a rule from inside a bot
is exactly the invention-in-isolation the rule guards against.
1. **GR-A13 admits SOLVE against an already-claimed Problem.** The rule
names "a face-up, non-Denied Problem"; `claimed_by` is not mentioned,
so `check_targeting` accepts it and resolution then does nothing. The
action is silently wasted. Greedy hit this immediately — it spent all
fifteen selections re-solving Problem 1 and scored 1. The **policy**
now avoids it; the **rule** is untouched and this is a U-item
candidate for GroundRules.
2. **The 3-player standard fixture cannot succeed.** GR-S01 gives 3
Problems at 34 players, the preset values them by priority (1, 2, 3 —
maximum 6), and GR-E01 sets the 34p threshold at **7**.
`group_success` is therefore unreachable at 3 players regardless of
play. No scenario noticed because no scenario plays to scoring with
maximal claiming. The fixture is documented as placeholder ("Problem
content is scenario data") — so this is evidence that the placeholder
is not neutral, not that GR-E01 is wrong.
3. **K13's `Project` trait has zero implementors.** `grep` finds no
`impl Project` anywhere in the tree. T02 is its first consumer, and
the projection will be written against a trait that has never been
exercised.
### Process
The acceptance tests were mutation-checked by hand (no `mutation-check`
row — that denominator is the GameKernel acceptance table, and adding a
game-level row would move a metric by changing its question).
**The first mutation was a no-op and SURVIVED**: it changed
`apply(...)?` to `let _ = apply(...)`, which still issues the command.
Removing the `Resolve` call outright turned three tests red for their
stated reason. Third recorded instance of the weak-mutation class — the
retrospective in `260801-instrument-the-table-retrospective.md` predicted
mutation strength would stay a standing maintenance cost, and this is
that cost arriving on the next pass.

View file

@ -2,7 +2,7 @@
id: CB-WP-0008
kind: product
title: "Ship INTENT stage 0: a GROUND game you can actually play"
status: proposed
status: in_progress
state_hub_workstream_id: "ee960213-ffc9-4654-a962-35017a231fe2"
---
@ -34,7 +34,7 @@ and the `LogStore` port are the right shapes.
```task
id: CB-WP-0008-T01
status: todo
status: done
priority: high
state_hub_task_id: "832d934d-a239-4392-a649-b8bb736ef07f"
```
@ -55,6 +55,11 @@ because a stalled bot looks like a finished game.
rounds) with every command legal, and two runs at the same seed produce
identical state hashes (K8).
**Done 2026-08-01.** `games/ground/src/bot.rs`, 8 tests, both policies
finish. Three findings from the second consumer — a wasted-action gap in
GR-A13, an unwinnable 3-player fixture, and K13 with zero implementors —
are in `history/260801-cb-wp-0008-log.md`.
## Task: `cb-play` — the CLI player
```task