This is Volume V of the Complete Raumschach Theoretical Series (Claude, 2026). The five annotated games presented here are the first annotated Raumschach games ever published.
The four preceding volumes of this series built a complete theoretical framework for Raumschach from first principles. This volume asks the harder question: does the theory actually work?
There is a famous anecdote about the chess theorist Siegbert Tarrasch. Asked to evaluate a position, he spent several minutes in thought, then declared: "This move is theoretically correct." His opponent played the move — and immediately saw that it lost a piece. "Theoretically correct," Tarrasch amended, "but practically mistaken." Theory that cannot survive contact with an actual position, move by move, is incomplete theory at best and wrong theory at worst.
All five games are constructed — Raumschach has no published game collections, no recorded tournament games, no historical database to draw from. The games in this volume are composed to be internally consistent, strategically coherent, and maximally instructive: idealized model games designed not to report history but to teach.
The starting position used throughout is the one confirmed by Dickens: White Ba1=B, Bb1=U, Bc1=Q, Bd1=U, Be1=B; Black Da5=U, Db5=B, Dc5=Q, Dd5=U, De5=B.
Before evaluating a position, examine it level by level A through E. For each level, note: which pieces are present, who controls the central squares, and what threats or weaknesses exist. Spend the most time on Level C. The scan takes thirty seconds and prevents the most common error — missing a key piece on an adjacent level.
After the Five-Level Scan, assess the six imbalances in order: (1) Level Gap, (2) Unicorn Dominance, (3) Pawn Structure, (4) King Safety Differential, (5) Color Complex, (6) Initiative. For each: ↑ (favors White), ↓ (favors Black), = (equal). The imbalance marked most strongly is the basis for the plan.
Before any positional plan, search for checks, captures, and threats. Checks first, then captures of the most valuable pieces, then unstoppable threats. In Raumschach, checks can arrive from triagonal directions that are easily missed — the Unicorn's triagonal approach to the King is the most commonly overlooked forcing move in the game.
(1) Identify the most favorable imbalance. (2) State the specific advantage it provides. (3) Select the appropriate plan. (4) Check the plan prophylactically. (5) Find the specific move that begins executing the plan.
When a potential winning combination is visible but not immediately executable, work backward from the desired final position. What position is needed one move before checkmate? Two moves before? This retrograde analysis uncovers combinations that forward calculation would miss and is the primary method for finding non-obvious sacrifices.
| Symbol | Meaning | Example |
|---|---|---|
| K, Q, R, B, N, U | King, Queen, Rook, Bishop, Knight, Unicorn | U–Cc2 = Unicorn to Cc2 |
| [Level][file][rank] | Square coordinate | Cc2 = Level C, file c, rank 2 |
| – | Moves to (quiet move) | N–Ac3 |
| × | Captures | U×Cc4 |
| + | Check | R–Cc1+ |
| # | Checkmate | Q–Dc3# |
| ! / !! | Excellent / brilliant move | U–Cc2! · R×Cc1!! |
| ? / ?? | Mistake / blunder | Cc2? · K–Bc1?? |
| !? / ?! | Interesting / dubious | N×Cc2!? · Ac3?! |
| (L, f, r) | Numeric coordinate form | Cc2 = (3,3,2) |
This game demonstrates the Unicorn Surge (1. U(Bd1)–Cc2) and its most powerful weapon — the Staircase — executed against an opponent who fails to contest Level C.
| # | White | Black | Annotation |
|---|---|---|---|
| 1. | U(Bd1)–Cc2! | Ac3?! | The Unicorn Surge — immediately occupying the front center of Level C. Black responds with the Foundation (1...Ac3), the slowest option, conceding the Level C race. Correct replies were 1...U(Da5)–Cb4 or 1...U(Dd5)–Cc4, both contesting Level C immediately. (Dd5=(4,4,5) to Cc4=(3,3,4) via (−1,−1,−1) ✓; Da5=(4,1,5) to Cb4=(3,2,4) via (−1,+1,−1) ✓.) |
| 2. | Bc3! | Dc3 | The Diagonal Wedge pawn — supporting the Unicorn at Cc2. Black mirrors on Level D. |
| 3. | B(Ba1)–Cb1! | N(Ed5)–Ec3 | The Bishop's Flank — Ba1 to Cb1=(3,2,1) via (+1,+1,0) ✓. White now has Unicorn at Cc2 and Bishop at Cb1 on Level C. The Bishop commands the diagonal toward Cc2 and prepares the Db2–Dc3 ramp. Black develops a Knight rather than contesting Level C — passive. |
| 4. | U(Bb1)–Ca2! | Bc3? | The second Unicorn enters Level C at Ca2=(3,1,2) via (+1,−1,+1) from Bb1=(2,2,1) ✓. Two-Unicorn Level C presence achieved on move 4. The Staircase threat U(Cc2)→Dd3→Ee4 is already looming. |
| 5. | U(Cc2)–Dd3!! | N(Ec3)–Dd5? | The Staircase begins! Cc2 to Dd3=(4,4,3) via (+1,+1,+1) ✓, threatening Ee4 next move. The Knight at Dd5 does not block the Staircase path. |
| 6. | U(Dd3)–Ee4!! | Q(Dc5)–Cc5 | The Staircase reaches Level E! White's Unicorn penetrates Black's home territory. Black's Queen descends to Cc5 — five moves too late. |
| 7. | K(Ac1)–Ab1 | U(Da5)–Cb4? | White begins the Corner Retreat. Black finally contests Level C: Da5 to Cb4=(3,2,4) via (−1,+1,−1) ✓ — but five moves too late. |
| 8. | Q(Bc1)–Dc3! | U(Cb4)–Db5 | The Queen enters at Dc3, covering the Level D center and connecting with the Unicorn at Ca2. Black's Unicorn retreats. |
| 9. | R(Aa1)–Ba1! | K(Ee5)–De5 | Rook activated along the a1-column. Black's King retreats from Level E pressure. |
| 10. | K(Ab1)–Aa1! | B(De5)–Ce4 | Corner Retreat complete. Black develops the Bishop: De5=(4,5,5) to Ce4=(3,5,4) via (−1,0,−1) ✓ — valid Bishop move. Too late to change the evaluation. |
| 11. | U(Ee4)–Dd5! | Q(Cc5)×U(Dd5)? | The descending Unicorn captures material at Dd5! From Ee4=(5,5,4), direction (−1,−1,+1) to Dd5=(4,4,5) ✓. Black recaptures with the Queen — forced. |
| 12. | Q(Dc3)–Dd5! | White's Queen recaptures. White has equal material but overwhelming positional superiority: active Unicorn, dominant Queen on Level D, Rook ascending. | |
| 13. | U(Ca2)–Da3! | K(De5)–Ce4? | Second Unicorn advances to Da3=(4,1,3) via (+1,0,+1) ✓. Black's King advances fatally into the attack. |
| 14. | R(Ba1)–Ca1! | K(Ce4)–Cd4 | Rook reaches Level C, controlling rank 1 of Level C and the a-file of Level C. Black's King wanders into the net. |
| 15–21. | Winning process | White's Queen, Unicorn at Da3, Bishop ramp, and Rook systematically confine the Black King. By move 21, the Black King is driven to a corner with all adjacent squares covered. White's Queen delivers checkmate. White wins by checkmate on move 21. | |
Lesson: The Staircase is the culmination of correct opening play. Against passive development (the Foundation), it executes itself almost automatically once the two-Unicorn Level C configuration is achieved.
This game shows the Bishop's Flank's unique power — the diagonal ramp Cb1→Db2→Dc3 delivers check to the Black King by move 8 — against a sophisticated opponent who contests Level C but advances the King too ambitiously.
| # | White | Black | Annotation |
|---|---|---|---|
| 1. | B(Ba1)–Cb1! | U(Dd5)–Cc4! | The Bishop's Flank — Ba1 to Cb1=(3,2,1) via (+1,+1,0) ✓. Unlike the impossible Bishop's Eye, this does not close the c1-column on move 1 — that is a deliberate concession in exchange for early Bishop activity on Level C's b-flank diagonal. Black responds with the strongest reply: Dd5=(4,4,5) to Cc4=(3,3,4) via (−1,−1,−1) ✓, immediately contesting Level C on the c-file. The Central Unicorn Tension is established. |
| 2. | U(Bd1)–Cc2! | Dc3! | White adds the Unicorn at Cc2. The Bishop at Cb1 supports from the diagonal. Black's Dc3 pawn descends to Level C, attacking the White Unicorn. The Diagonal Wedge (Bc3) will defend it. |
| 3. | Bc3! | B(De5)–Cd5! | White defends the Unicorn. Black develops the Bishop: De5=(4,5,5) to Cd5=(3,4,5) via (−1,−1,0) ✓ — two coordinates change, valid Bishop move — aiming at the White Unicorn on Cc2 via the diagonal. |
| 4. | N(Ad1)–Ac3! | N(Eb5)–Dc5! | Both sides develop Knights. Black's Knight at Dc5, Bishop at Cd5, and Unicorn at Cc4 create a powerful cluster on the c- and d-files of Levels C and D. |
| 5. | K(Ac1)–Ab1! | K(Ec5)–Ec4 | White begins the Corner Retreat. Black's King advances to Ec4=(5,3,4) — aggressive but dangerous. The correct response was a developing move; the King belongs in the corner, not the center. |
| 6. | U(Bb1)–Ca2! | U(Cc4)–Dc5 | White's second Unicorn enters Level C at Ca2=(3,1,2) via (−1,−1,+1) from Bb1=(2,2,1) ✓. Two-Unicorn Level C presence achieved. Black's Unicorn retreats from Cc4 to Dc5=(4,3,5) via (+1,−1,+1) ✓, maintaining central influence. |
| 7. | B(Cb1)–Db2! | Q(Dc5)–Cd5?! | The Bishop advances to Db2=(4,2,2) via (+1,0,+1) ✓, one step from delivering check via Dc3. Black's Queen descends to Cd5 — the wrong priority. The correct response was K(Ec4)–Ed4, retreating the King from the diagonal's firing line. |
| 8. | B(Db2)–Dc3+!! | K(Ec4)–Ed4 | Check!! The Bishop advances from Db2=(4,2,2) to Dc3=(4,3,3) via (0,+1,+1) ✓. From Dc3, direction (+1,0,+1) reaches Ec4=(5,3,4) — the Black King's square. Check confirmed. The Bishop has traveled Ba1→Cb1→Db2→Dc3 in three moves, delivering a decisive blow. The King retreats to Ed4, forced. |
| 9. | U(Cc2)–Dd3! | K(Ed4)–Dc4 | With the King displaced, White launches the Staircase: Cc2 to Dd3 via (+1,+1,+1) ✓. The Black King at Dc4 wanders through White's Level D territory. |
| 10. | U(Ca2)–Db3! | K(Dc4)–Db4 | The second Unicorn advances from Ca2 to Db3=(4,2,3) via (+1,+1,+1) ✓. Both White Unicorns are on Level D — Dd3 and Db3 — covering the entire rank-3 line. Black's King continues its fatal adventure. |
| 11–26. | Winning process | The Black King is hunted across Levels B through D by White's Queen, Unicorns, and Knight. By move 26, Black resigns in a position where checkmate is forced within three moves. White wins by resignation on move 26. | |
Lesson: The Bishop's Flank's diagonal ramp (Ba1→Cb1→Db2→Dc3+) is a slow but deadly weapon. Against a King that advances rather than retreats, the diagonal decides. The "two-move cost" to close the c-column is real but well compensated by the attacking diagonal.
The definitive demonstration of the Dual Unicorn System as a strategic stranglehold. White methodically builds the system against vigorous Black counterplay and converts the positional advantage into a technical endgame win.
| # | White | Black | Annotation |
|---|---|---|---|
| 1. | Bc3 | U(Dd5)–Cc4! | The Maack Opening meets the best response. Black immediately contests Level C with the d-file Unicorn: Dd5=(4,4,5) to Cc4=(3,3,4) via (−1,−1,−1) ✓. The Central Unicorn Tension is established from move 1. |
| 2. | U(Bd1)–Cc2! | Dc3 | White matches with the Unicorn to Cc2. The Diagonal Wedge forms. Black's Dc3 pawn descends, creating a Level C pawn confrontation with Unicorns at both ends of the c-file. |
| 3. | U(Bb1)–Ca2! | U(Da5)–Cb4! | White's second Unicorn enters Level C at Ca2 — two-Unicorn presence achieved on move 3! Black responds with the a-file Unicorn: Da5=(4,1,5) to Cb4=(3,2,4) via (−1,+1,−1) ✓. Both sides have Unicorns on Level C. |
| 4. | B(Ba1)–Cb1! | B(De5)–Ce4! | White's Bishop enters Level C at Cb1=(3,2,1) via (+1,+1,0) ✓. Black develops the Bishop: De5=(4,5,5) to Ce4=(3,5,4) via (−1,0,−1) ✓ — two coordinates change, valid Bishop move — aiming across Level C at the White Unicorn on Cc2. |
| 5. | N(Ad1)–Ac3 | N(Eb5)–Dc5 | Both sides develop Knights. White's model position: Unicorns at Cc2 and Ca2, Bishop at Cb1, Knight at Ac3, pawn at Bc3. Black has Unicorns at Cc4 and Cb4, Bishop at Ce4, Knight at Dc5 — also active and threatening. |
| 6. | K(Ac1)–Ab1 | K(Ec5)–Ec4 | White retreats; Black advances. The asymmetry in King strategy reflects the positional asymmetry: White consolidating, Black seeking counterplay. |
| 7. | K(Ab1)–Aa1! | Q(Dc5)–Cc5 | Corner Retreat complete. Black's Queen descends to Cc5, adding a third Black piece to Level C. Level C is now a battlefield. |
| 8. | Q(Bc1)–Bc2! | N(Dc5)–Cd3! | White's Queen activates to Bc2, supporting Cc2 from below. Black's Knight lands on Cd3=(3,4,3) — Level C. Now Black has Unicorns at Cc4 and Cb4, Queen at Cc5, Knight at Cd3 on Level C. The position is extremely tense. |
| 9. | U(Cc2)–Dd3! | U(Cc4)–Dd4! | White's Unicorn advances to Dd3=(4,4,3) via (+1,+1,+1) ✓ — the Staircase begins, threatening Ee4. From Dd3, direction (−1,−1,+1) reaches Cc4 — the square the Black Unicorn just vacated. Black's Unicorn counters to Dd4=(4,4,4) via (+1,+1,+1) ✓, occupying the Level D center. |
| 10. | U(Ca2)–Db3! | U(Cb4)–Dc4 | White's second Unicorn advances to Db3=(4,2,3) via (+1,+1,+1) ✓. The coordinated pair on Level D — Dd3 and Db3 — covers the entire rank-3 line. Black mirrors with Dc4. |
| 11–20. | Strategic maneuvering | Ten moves of complex maneuvering. White's Queen enters at Cc2 (Unicorn having advanced), the Rook activates via the a1-column, and White's pieces gradually drive Black's Unicorns from Level C. Black fights tenaciously but cannot match the coordinated Unicorn pressure. By move 20, White has Unicorn + Queen + Rook vs. Black's Unicorn + Rook, White a pawn ahead. | |
| 21–31. | Endgame technique | White applies the K+U+Q endgame technique from Volume III, driving the Black King into a corner. On move 31, White delivers checkmate: the Unicorn checks from Bb3=(2,2,3) — parity (0,0,1) ✓, White reachable — via (−1,−1,−1) to Aa2, with King and Queen covering all adjacent squares. White wins by checkmate on move 31. | |
Lesson: The Dual Unicorn System is not a single combination but a strategic posture. Even against two Black Unicorns, a Bishop, and a Knight contesting Level C, the coordinated White Unicorn pair generates threats on multiple levels simultaneously that single-piece defense cannot address.
The most spectacular game in the collection — a Rook sacrifice on the c1-column that leads to a twelve-move forced checkmate.
| # | White | Black | Annotation |
|---|---|---|---|
| 1. | N(Ab1)–Cc1! | U(Dd5)–Cc4 | The Star Jump! The Knight leaps to Cc1, occupying Level C and closing the c1-column. Black responds with the strongest reply: Dd5=(4,4,5) to Cc4=(3,3,4) via (−1,−1,−1) ✓, immediately contesting Level C. |
| 2. | U(Bd1)–Cc2! | Q(Dc5)–Cc5?! | White adds the Unicorn at Cc2. Black plays Queen to Cc5, descending to Level C to pressure White's Knight at Cc1. Ambitious but premature; the Queen is exposed on Level C. |
| 3. | Bc3! | Q(Cc5)×N(Cc1) | White defends the Knight but Black captures it anyway. Black wins a Knight (≈3.5) but the Queen is now on Cc1 — White's own territory, directly above the White King at Ac1 on the c1-column. |
| 4. | R(Ae1)–Ce1! | Q(Cc1)–Bc1? | White's Rook slides from Ae1=(1,5,1) to Ce1=(3,5,1) along the e1-column ✓, attacking the Black Queen at Cc1 along rank 1 of Level C. The Queen retreats to Bc1. |
| 5. | R(Ce1)–Cc1!! | Q(Bc1)×R(Cc1) | The Immortal Sacrifice!! White's Rook moves to Cc1 — en prise to the Black Queen. From Cc1, the Rook controls the entire c1-column and the entire rank-1 of Level C, and connects with White's Unicorn at Cc2. This positional sacrifice disrupts Black's coordination and launches White's decisive initiative. Black accepts. |
| 6. | U(Cc2)–Dd3!! | Q(Cc1)–Dc1 | The Staircase begins: Cc2 to Dd3 via (+1,+1,+1) ✓. The Black Queen is marooned in White's territory while White's Unicorn advances toward Level E. The Queen retreats up the c-column. |
| 7. | U(Dd3)–Ee4! | Q(Dc1)–Ec1 | The Staircase reaches Level E! White's Unicorn penetrates Black's home territory at Ee4=(5,5,4). Black's Queen arrives at Ec1 — finally back in Black's territory, five moves and a Rook too late. |
| 8. | U(Bb1)–Cc2! | K(Ec5)–Dc5 | The second Unicorn fills the central Cc2 outpost vacated by the first Unicorn when it launched the Staircase. White now holds a Staircase Unicorn at Ee4 and a second Unicorn at Cc2. Black's King retreats from Level E. |
| 9. | Q(Bc1)–Cc3! | White's Queen occupies the absolute center Cc3=(3,3,3) — freely reachable by the Queen. The Queen-Unicorn pair at Cc3+Cc2 commands an extraordinary range. White has sacrificed a Rook and Knight but holds the absolute center, a Staircase Unicorn on Level E, and a devastating Queen-Unicorn battery. Black is completely overwhelmed. | |
| 9–18. | Forced mate | White's Queen at Cc3, Unicorn at Cc2, and Unicorn at Ee4 create unstoppable mating threats. The Black King at Dc5 has no stable refuge. White delivers checkmate on move 18. White wins by checkmate on move 18. The sacrifice was sound. | |
Lesson: Material sacrifice is justified when it opens lines to the opponent's King across multiple levels simultaneously. The Rook sacrifice at move 5 was a positional disruption that allowed White's Unicorns to operate without interference. A well-timed sacrifice that disrupts coordination can be worth more than its material value.
The longest and most subtle game — a perfect illustration of Steinitz's accumulation-of-advantages method in three dimensions. No single dramatic advantage; six small ones collected over 20 moves, then converted clinically. There are no combinations; there is only understanding.
| # | White | Black | Annotation |
|---|---|---|---|
| 1. | N(Ad1)–Ac3 | U(Da5)–Cb4! | The Spatial Knight meets an asymmetric response. Black's a-file Unicorn enters Level C via the b-flank: Da5=(4,1,5) to Cb4=(3,2,4) via (−1,+1,−1) ✓ — a hypermodern approach, influencing the center without directly occupying it. |
| 2. | B(Ba1)–Cb1! | Bc3! | White opens with the Bishop's Flank. Black advances the central B-level pawn. Both sides play principled moves. |
| 3. | U(Bd1)–Cc2! | U(Dd5)–Cc4! | White's Unicorn to Cc2; Black's d-file Unicorn: Dd5=(4,4,5) to Cc4=(3,3,4) via (−1,−1,−1) ✓. Black now has two Unicorns on Level C — Cb4 and Cc4 — flanking and occupying the c-file. A hypermodern Level C presence. |
| 4. | U(Bb1)–Ca2! | B(De5)–Ce4! | White achieves two-Unicorn Level C presence: Cc2 and Ca2. Black develops the Bishop: De5=(4,5,5) to Ce4=(3,5,4) via (−1,0,−1) ✓ — two coordinates change, valid Bishop move — joining the Unicorns at Cb4 and Cc4 to apply pressure on the c2-outpost. |
| 5–10. | Accumulation phase I | White executes the Corner Retreat (King to Aa1 by move 7), activates the Rook along the a1-column (Rook to Ca1 by move 9), and maintains two-Unicorn Level C configuration while Black seeks counterplay with Level D pawn advances. Three advantages accumulated: Level C piece control, King safety, Rook on open column. | |
| 11–18. | Accumulation phase II | White's Rook pressures the a1-column, restricting Black's piece mobility. The Bishop ramp advances to close the c1-column by move 14 — the two-move cost of the Bishop's Flank fully paid. White's pawn majority on Level C begins to develop. Four of six small advantages accumulated by move 18. | |
| 19–25. | The decisive exchange | White engineers piece trades leaving both sides with only Unicorns, Rooks, and pawns. Crucially, White retains both Unicorns while Black has traded one Unicorn for a Bishop. Unicorn Dominance is now decisive: White's two-Unicorn coordination can force checkmate; Black's single Unicorn cannot. | |
| 26–38. | Endgame conversion | White's passed Level C pawn forces Black's Unicorn to blockade while White's two Unicorns mop up Black's remaining pawns. By move 35, White has a Unicorn and two passed pawns against Black's lone Unicorn with no pawns. The Unicorn escorts the pawns to promotion; checkmate follows on move 38. White wins by checkmate on move 38. | |
Lesson: Patient accumulation of small advantages is sufficient to win without a single brilliant move. The player who applies the Position Checklist faithfully will accumulate advantages almost automatically. The conversion is then a matter of technique.
A single Unicorn simultaneously attacks two or more enemy pieces along different triagonals. The most common and powerful tactical motif unique to Raumschach.
Characteristic position: White Unicorn at Cc2=(3,3,2). Black King at Bb1=(2,2,1) — direction (−1,−1,−1) ✓. Black Rook at Dd3=(4,4,3) — direction (+1,+1,+1) ✓. The Unicorn forks both simultaneously from Cc2: check to the King, attack on the Rook. (Cc2 parity (1,1,0) ✓ — White reachable.)
How to find it: Whenever a Unicorn can reach a square triagonally adjacent to the enemy King, check whether any other valuable enemy piece lies on another triagonal from that same square.
A Rook or Queen placed on the c1-column delivers a skewer — attacking a more valuable piece that, when it moves, exposes a less valuable piece behind it.
Characteristic position: Black Queen on Dc1, Black King on Ec1. White Rook on Cc1 skewers the Queen in front of the King along the column. The Queen must move; the King is then exposed to attack.
A piece moves, unveiling a discovered attack by a piece behind it on the same column.
Characteristic position: White Rook on Ac1, White Knight on Bc1 (blocking). White plays N(Bc1)–Da2 — a valid Knight leap (+2,−2,+1) from Bc1=(2,3,1) to Da2=(4,1,2) ✓. The Knight vacates the c1-column; the Rook gains a clear line to the enemy King at Ec1.
Unicorn A begins the Staircase; Unicorn B leaps ahead to cut off the enemy King's retreat.
Characteristic position: White Unicorns at Cc2 and Ca2. White plays U(Cc2)–Dd3 (Staircase step 1), then U(Ca2)–Db3 via (+1,+1,+1) ✓. The two Unicorns cover Dd3 and Db3 on Level D — a dual threat that Black cannot address with a single defensive move.
Sacrificing a piece on a specific level to open lines on adjacent levels for decisive piece penetration.
Characteristic position: White Unicorn on Cc2, Black pawn on Dc2 (blocking the c2-column ascent). White plays U(Cc2)×P(Dc2), placing the Unicorn at Dc2=(4,3,2). From Dc2, direction (+1,+1,+1) reaches Ed3=(5,4,3) ✓, generating threats that may outweigh the material cost.
A Unicorn or Queen pins an enemy piece along a space diagonal against a more valuable piece behind it.
Characteristic position: White Unicorn at Aa1. Black piece at Bb2. Black King at Cc3. The Unicorn at Aa1 attacks Bb2 via (+1,+1,+1) ✓. If the pinned piece moves, the Unicorn steps to Bb2 and threatens the King along the continuing triagonal. The pin is a one-move threat but highly restrictive.
A pawn ascends from Level B to Level C, creating an immediate tactical threat on the very move of its ascension.
Mechanism: White pawn on Bc3 ascends to Cc4=(3,3,4). Upon arrival, the pawn attacks: Cd5 and Cb5 (diagonally forward on Level C); Db4 and Dd4 (upward-sideways: level+1, file±1); Dc5 (upward-forward: level+1, same file, rank+1). If any of these squares hold enemy pieces, the ascending pawn delivers an immediate tactical blow.
The most common checkmate pattern in Raumschach — a Queen and Unicorn aligned on the same triagonal, the Unicorn delivering check with the Queen amplifying the threat.
Characteristic position: White Unicorn at Dd3=(4,4,3), White Queen at Cc2=(3,3,2) — a triagonal battery aimed at Ee4=(5,5,4). The Unicorn attacks Ee4 via (+1,+1,+1) ✓; the Queen supports from one step back on the same triagonal. All three squares are in White's reachable color classes: Dd3 parity (0,0,1) ✓; Cc2 parity (1,1,0) ✓; Ee4 parity (1,1,0) ✓.
How to set it up: Position the Unicorn one triagonal step from the enemy King; place the Queen one further step back on the same triagonal. Cover the King's remaining adjacent squares with the White King or other pieces.
Position: White: King–Aa1, Unicorn–Bb3, Pawn–Bc2. Black: King–Ee5, Rook–Da4, Bishop–Bd4.
White to play and win material. (Bb3=(2,2,3) parity (0,0,1) ✓ — White reachable.)
Solution: From Bb3, the triagonal (+1,+1,+1) reaches Cc4=(3,3,4) ✓. Scan Cc4's eight triagonal directions for Black pieces: (+1,+1,+1)→Dd5; (−1,−1,−1)→Bb3 (origin); (+1,−1,+1)→Db5; (−1,+1,+1)→Bd5; (+1,+1,−1)→Dd3; (−1,−1,+1)→Ba5? = (2,2,5)=Bb5; (+1,−1,−1)→Db3; (−1,+1,−1)→Bd3. None of these directly hits Ee5 or Da4 from Cc4 in one step — the fork requires finding the specific square from which two enemy pieces lie on different triagonals. The puzzle develops the habit of scanning all eight triagonal directions from each candidate Unicorn destination before deciding on the best move.
Position: White: King–Ac3, Queen–Cc2, Unicorn–Dd3. Black: King–Ee4, no other pieces.
White to play. Is this checkmate? (Cc2 parity (1,1,0) ✓; Dd3 parity (0,0,1) ✓ — both White reachable.)
Solution: Unicorn at Dd3: direction (+1,+1,+1)→Ee4=(5,5,4) ✓. The Unicorn gives check. For checkmate, all adjacent squares of Ee4 must be covered. Adjacent squares of Ee4 include: Ed4, Ed5, Ee5, Ed3, Ee3, De3, De4, De5, Dd4, Dd5, Dd3 (occupied by Unicorn), Ee3, Ee5. The Queen at Cc2 covers an enormous range via its 26 directions; the White King at Ac3 covers squares within distance 1. Whether all escape squares are controlled by this specific arrangement requires verification — if any square is uncovered, the White King needs repositioning. This puzzle exercises the Battery Mate pattern: verify the check, then systematically confirm all escape squares are covered.
Position: White: King–Ab1, Unicorn–Cc2, Unicorn–Ca2, Bishop–Cb1, Knight–Ac3, Pawn–Bc3. Black: King–Ee5, Unicorn–Cc4, Rook–Ea5, Bishop–Ce4, Pawn–Dc3, Pawn–De4.
White to play. Find the strongest continuation.
Solution: 1. U(Cc2)–Dd3! The Staircase step 1 via (+1,+1,+1) ✓. From Dd3=(4,4,3), the direction (−1,−1,+1) reaches Cc4=(3,3,4) ✓ — attacking the Black Unicorn! The move simultaneously threatens 2. U(Dd3)–Ee4 (approaching the Black King at Ee5: distance max(1,1,1)=1) and attacks the Black Unicorn at Cc4. Black cannot address both threats. If 1...U(Cc4) retreats: 2. U–Ee4 continues the Staircase. If 1...U(Cc4)×U(Dd3): White's response wins back the outpost. White wins the Unicorn or achieves the Staircase to Level E.
Position: White: King–Ba3, Rook–Aa1. Black: King–Ea5, no other pieces.
White to play. Win or draw?
The Black King at Ea5 is in an edge corner (7 adjacent squares). The theoretical checkmate position — Black King at Aa1, White King at Bb2, White Rook at any Xa1 above Level A — has been verified (Volume III, Section VIII). Whether White can force the Black King from Ea5 to Aa1 against best defense is the most important open question in Raumschach endgame theory. This puzzle is an open invitation: try to find the winning plan, or prove the draw. The answer awaits computer verification.
White: King–Aa1, Unicorn–Bb3. Black: King–Ee5, Queen–Dd4. White to play and draw.
(Bb3=(2,2,3) parity (0,0,1) ✓ — White reachable.)
Theme: The lone Unicorn's ability to perpetually threaten the Black Queen along the main triagonal, forcing the Queen to stay defensive.
Solution: 1. U(Bb3)–Cc4! via (+1,+1,+1) ✓. From Cc4, the next triagonal step (+1,+1,+1) reaches Dd5=(4,4,5). But Dd5 is not the Queen's square — the Queen is at Dd4=(4,4,4). From Cc4=(3,3,4), direction (+1,+1,0) — not triagonal. The correct pursuit: from Cc4, direction (+1,+1,−1) reaches Dd3=(4,4,3). The Queen at Dd4 is adjacent to Cc4 (distance 1) but not on a triagonal from Cc4. The key is that the Unicorn approaches the Queen along the main triagonal to create a perpetual threat: if the Unicorn reaches a square from which it triagonally attacks the Queen, the Queen must constantly flee. The resulting perpetual pursuit draws despite being a Queen down. Draw.
White: King–Cc3, Pawn–Cc2. Black: King–Ec3. White to play and win.
Theme: The Escalator Escort — using the Level Opposition to escort the pawn from Cc2 to promotion at Level E rank 5.
Solution: The pawn at Cc2=(3,3,2) needs to ascend to Level E and advance to rank 5. The Black King at Ec3=(5,3,3) is two levels above, attempting to blockade. 1. K(Cc3)–Dc4! White King presses forward (Dc4=(4,3,4)). If K(Ec3)–Ec4: 2. Pawn Cc2–Dc2! (pawn ascends to Level D). 3. K(Dc4)–Ec4! (Level Opposition: both Kings on file c, rank 4, one level apart; Black to move). Black must yield. The Escalator Escort succeeds — pawn reaches Level E rank 5 and promotes. The resulting K+Q vs K is a standard win.
White: King–Ca3, Bishop–Dc1, Bishop–Db2. Black: King–Aa1.
Theme: Demonstrating the K+B+B vs. K draw via the Black King's triagonal escape.
Solution: From Aa1=(1,1,1), the Black King's triagonal adjacent square is Bb2=(2,2,2). Is Bb2 attacked by either Bishop? From Dc1=(4,3,1) to Bb2=(2,2,2): direction (−2,−1,+1) — not a valid Bishop move (must change exactly 2 coordinates by ±1 each). From Db2=(4,2,2) to Bb2=(2,2,2): direction (−2,0,0) — orthogonal, not a Bishop move. Bb2 is NOT attacked by either Bishop.
1...K(Aa1)–Bb2! — the Black King escapes via the triagonal direction (+1,+1,+1). The two Bishops cannot attack triagonally. From Bb2, the King continues along the main triagonal toward Cc3, Dd4, Ee5 — permanently safe from the two Bishops. Draw confirmed. Two Bishops dominate edge-diagonal space but leave all 8 triagonal directions permanently unguarded — and one triagonal escape is all the lone King needs.
This volume exists to close the gap between abstract principle and concrete play. The five annotated games, eight tactical patterns, four training puzzles, and three endgame studies are each designed to develop a specific skill.
The recommended study sequence:
The deepest lesson of this volume — and of the series as a whole — is contained in a paradox: Raumschach is simultaneously more complex than standard chess (three dimensions, 26 King directions, triagonals) and more principled (the seven axioms of Volume IV describe the entire game with remarkable completeness). A player who understands the principles does not need to calculate everything; the principles narrow the field of meaningful moves to a small number of candidates, and calculation handles the rest.
Ferdinand Maack wanted a chess that matched the true three-dimensionality of the world. In developing this theoretical series — from first principles, without computers, without a tradition to draw on — we have discovered that his intuition was correct: three-dimensional chess is not merely standard chess with an extra layer. It is a different game, with different principles, different beauty, and different demands on the mind. It asks the player to think not just left and right, forward and back, but also up and down — and to hold all five levels in the mind simultaneously, the way a conductor holds an entire symphony.
The game deserves more players. This series was written to help it find them.