Gridparlix

Gridparlix is a parity dispatch puzzle set in a stylised urban transit grid.

Two parallel lanes of numbered cards stretch across the dashboard. You command a pointer on each lane and decide turn by turn which one to advance. Every absorbed card adds to that lane's running total. The route clears when one pointer finishes its lane and the absolute difference between the two totals lands inside the epsilon tolerance band.

The twist is the turn budget. You may have fewer turns than there are cards in total, which forces sharp allocation between the two lanes. A naive lower-total-lane greedy advance is rarely the right call. Look ahead, count, and place each move where it tightens the final gap.

Three tiers of difficulty are available. Subway Commute is a short tutorial-friendly route with eight cards per lane and a generous epsilon. Express Line stretches the planning horizon to fourteen cards per lane. High-Speed Junction adds three special card types to the grid. Spike traps absorb a turn while still adding their value. Mirror swaps instantly exchange the two running totals. Pivot cards force your next turn to the opposite lane.

A dashboard panel shows lane totals, current difference, turns remaining and a visual safety band meter. A pre-route briefing overlay explains the tier and lets you study the board before any move. After every clear or out-of-sync result a celebration screen breaks down the dispatch.

The Journey Trail Logbook stores recent dispatches with outcome ribbons and a step ratio strip. The Conductor Insignia Cabinet collects six merit badges including perfect parity, solo lane run, symmetric dispatch, spike evader, mirror reversal and a five-route streak. The Operations Briefing is a full handbook of the rules, the special cards and the strategic guidance.

Gridparlix rewards quiet planning, lane reading and clean parity discipline. There is no pressure clock, only the turn budget and the slow tightening of the difference number.