FideLite Variant Generator

Generates a single-file chess engine from your selections. (single period)

Interface DOM (clickable) Input (text box) Prompt (blocking)

Info mode Counted (M= R=) Strict (move history) Blindfold (no board)

Board rotation Rotate to side on move

Rules Standard Freestyle / Chess960 (generic)

Rule set FIDE USCF

FIDE: 5-fold & 75-move are automatic draws; a resign with no mating material is a draw. USCF: no automatic 5-fold/75-move draw (the 3-fold/50-move claim still works) and a resignation always loses. Move rules, interface, clocks are identical.

draw-offer limit (full moves)

1 = no limit. ≥2 would cap each side to one draw offer per N of their own full moves (a 50-move/3-fold claim is always allowed). Reserved: offer throttling is being reworked and is currently inactive — every offer goes through regardless of this value.

Position ID (0–959, Scharnagl)

Arrangement (8 letters, K between the two R)

518 = standard start

Time mode Fischer (increment) Simple delay Bronstein (add-back) Sudden death

White (min)

Black (min)

Same time for both

Increment/delay (s)

2nd period

at move

add (s)

inc (s)

3rd period

at move

add (s)

inc (s)

Multi-period (input · DOM · prompt). Each side gets the added time when it completes the threshold move. Per-period inc (blank = same as period 1) lets the increment activate later, e.g. 0→30s; input/DOM only. All increments 0 ⇒ sudden template (minimum bytes).

FEN (optional)

Empty = initial position. Works together with 960 too; castling rights are checked against the arrangement rooks. The castling field accepts classic (KQkq) or Shredder-FEN (rook file letters: A-H white, a-h black).

Side Castling K Q k q EP ½move Repetition

FEN (reflects the board · paste one to load it)

basic_core.js

⚠ bare‑core fell out of sync with build() — a core function changed. Update the code string in the panel wiring.

Strip away every interface and time control, and this is the whole engine — move generation plus state: the board string, the clocks, and the move counter. No prompt, no board render, just move().

engine.js —

periods

123

replaced in this variant added for this variant

Same engine, different interface. The buttons above reshape the rules; these reshape how the game is presented and played.

engine.js —

interface prompt / input / clickable notation counted / strict / blindfold rotation board flips on move

Technical info — coming soon.

Game Rules — coming soon.

FideLite PGN tester

Replays a historical game through FideLite's own engine (Standard or Chess960) and shows its reaction at every half-move. SAN is converted to the engine's moves with its own legal-move generator. No clock in the logic — each ply just renders ~1s apart so it's watchable. The game does not auto-end on the PGN's last move; natural endings (mate, stalemate, 3/5-fold, 50/75-move, dead position) stop it. Flag drop is manual; the engine decides win-vs-draw (TM/RM).

PGN

Move list

No game loaded.

A flag drop / resign both report as a flag-fall; the engine rules win vs draw (TM = can't mate ⇒ draw).

side to move—

ply / move #—

M · halfmove clock (o)—

R · repetition count—

ep target (Y)—

castling (C)—

in check J(T)—

last UCI—

engine verdict z—