Maps

Stages and tiers (DESIGN §4b)

The model (sim/src/objective.rs Stage, map.rs StageDef, authored stage / obj / fwd records):

• A map is a row of stages in attack order. A stage is 2-3 objectives per sector; the map says how many must fall (need: any N of them in any order, or all). The last stage is one final objective: Domination's command centre (take it, then hold it while the bar fills, final_hold_s 60 s; defenders standing on it alone take it back), Sabotage's C (plant and guard the charge), Acquisition's escort (both vehicles out).
• Taking a stage opens the next; stages never close again (Sabotage: once A and B are held together, C stays open). The stage's untaken objectives drop out.
• Spawns move with the stages. Every stage before the last has a bunker per column behind its objectives (fwd): the defenders spawn at the current stage's bunker while it stands (else the next stage's, else home); once the stage falls its bunkers are the attackers' forward spawns (the one nearest their objective). Attackers start at their home camp on the map edge.
• The path. Each stage lies at least stage_gap_<tier>_m beyond the last (pacing.txt), across ground with cover rows every 20-30 m, two 8 m vehicle lanes, ridges for defilade between the stages and a berm in front of the home camp (tools/maps/stagegen.mjs). Every objective has two ways in from where the attackers spawn for it (sim tests/stage_maps.rs: the shortest walk is shut 25 m either side and the objective must still be reachable).
• Clock per stage. A stage opens with at least stage_min_s (360 s) on the clock; taking one adds stage_bonus_s (300 s). The clock running out is a defeat (minor if the attackers reached the final stage).
• Modes keep their rules inside a stage (StageRule): Capture (taken for good), HoldTogether (Sabotage's uplinks, both at once; a held uplink is re-secured at uplink_retake_mul), Final, Charge (planting and defusing go to the side with more people on C), Escort, DamageBar (generated maps play MAG's three tiers as stages).
• Bots work the current stage only: the attackers of a sector mass on one open objective of the stage at a time; the defenders spread over the open ones and one squad in four digs in on the next stage's line; when the stage falls everyone moves on (defenders fall back). FRAGOs, orders and Kev's state snap onto the current stage (defenders: also the next). A FRAGO left on a fallen stage lapses.
• HUD: the stage pips, the live objectives (■ held, ◩ being taken, □ open) and the stage clock in the win strip and the match strip; a banner when a stage falls; the minimap and the deploy map grey out the locked stages and show the stage bunkers (protocol 9: the mode block carries the stage and the stage count).

Tiers (map::SIZE_TIERS; the map names its tier with tier NAME players):

The traced maps grew instead of shrinking their walks: Caspian's refinery is now the final arena of a 1.9 km map (stage 1 at 730 m from the core, stage 2 at its fence), Alyeska's terminal sits in a 1.9 km map (stage 2 on its burn-off landmarks), Kennick gained a forested east approach and Halden a southern one. On the cross maps the defenders' home camps moved from 40 m off the core to the diagonals 150 m out (the final objective sat inside them). The bench (tools/stage-bench.sh, 8 runs, 1200 s) has the attackers winning 3-4 of 8 on every map (mapflow, before home camps and the NORMAL bot tier; the integrate numbers are in §4c).

Lore pages (who holds each map, landmarks, palette, sound, music, screenshots) for all 8 maps, including the ones still on the maps branch: Caspian Refinery · Alyeska Terminus · Kennick Rail Yard · Halden Bay Depot · Vesna Crossing · Kolva Ridge · Grey Front · Soroka Yard.

Map scale and the war map (DESIGN §20.5)

How to read the table:

• Rows are the 64-player Conquest Large layer plus the shared conquest layer, which holds the HQs and common spawners on several levels (maps.json).
• Bounds are the bounding box of the largest combat-area polygon that contains every flag. Caspian and Paracel use a wide air polygon.
• NN is the median distance from each flag to its nearest flag.
• Uncap is the distance from each HQ to its nearest flag.
• Per-side vehicle counts use the order MBT/IFV/AA/light car/heavy car/bike/attack heli/scout heli/ transport heli/attack jet/fighter jet/boat/static AT/static AA. Each spawner was assigned to its nearest HQ. When the two sides differ, the cell shows US|RU.
• Flag spawns are the outposts that belong to whoever holds the flag.
• Level names: level ids are matched to map names by their codenames. Only mp_damage, mp_flooded and mp_thedish have descriptive SIDs.

What the table says, at 32 players a side:

• 5–7 flags. Median flag spacing is 201 m (range 124–272 m).
• HQ to HQ is a median 1093 m (range 716–1669 m). HQ to first flag is a median 376 m (115–538 m).
• Per side: 2–5 MBTs; IFVs and AA 0–3; 1–3 aircraft. Jets appear on maps of 2 km or more.
• Flags hand out the light transport.
• Small maps (Zavod, Shanghai, Flood Zone) still field 1–2 MBTs per side in about 1 km².
• Not in data: per-instance respawn timers; capture radius and capture time per flag; ticket counts.

Our rules per tier. A sector is 500 × 500 m. A side's numbers scale with sector count, which tracks area, never with player count (DESIGN §19.1). BF4 puts roughly 5 armour and 2 aircraft per side on 1–3 km² of ground for 32 players. We put about 1 armour per sector for 32 players (one platoon).

Our uncap distances are shorter than BF4's 376 m median. The reason is §19.3: two minutes on foot to the fight, and the APC and transport heli are the forward spawns.

Worked layout: the 8-sector war map (2000 m along x, 1000 m along z; attack runs south → north).

 z=1300 ┌ defender air uncap (jet, 2 helis), counter-drone battery #2 ─────────────────────────┐
 z=1000 ├────────────┬────────────┬────────────┬────────────┤  defender home camp: AA, motor pool
        │ S5  C·B·A  │ S6  C·B·A  │ S7  C·B·A  │ S8  C·B·A  │  inner belt; CORE-W between S5/S6,
        │            │            │            │            │  CORE-E between S7/S8 at z≈950
 z=500  ├────────────┼────────────┼────────────┼────────────┤  ridge line (DESIGN §17), APC lanes
        │ S1  C·B·A  │ S2  C·B·A  │ S3  C·B·A  │ S4  C·B·A  │  outer belt; burn-off zones at z≈120
 z=0    ├────────────┴────────────┴────────────┴────────────┤  attacker berm at z≈-60
 z=-300 └ attacker air uncap; home camp spawn at z≈-180: MBT ×4, APC ×8, AA ×2, helis, jet, battery #1 ─┘
        x=0          500          1000         1500         2000

• Zones. Each sector has A at z+120, B at z+280, C at z+430 (tiers 0/1/2). That is 24 zones plus 2 cores. Along the attack axis, zones are 150–190 m apart (C of S1 to A of S5 is 190 m), close to BF4's 201 m median. Across the map they are 500 m apart. Attacker spawn to the first A zone is 300 m.
• Platoons. Each of the 8 platoons (32 players) owns one sector. Platoons 1–4 open on S1–S4; platoons 5–8 ride the APCs up to S5–S8 as the outer belt falls. That is the server partition (DESIGN §9).
• Where vehicles spawn.
  • One APC per platoon at the home camp, 90 s.
  • MBTs at x ≈ 250 / 750 / 1250 / 1750, one per 2 sectors, 60 s.
  • Trucks at every captured A and B zone, 2 per sector, 40 s.
  • AT emplacements at captured B and C zones.
• Air. Air bounds run 300 m past each ground edge (2600 × 1600 m), like BF4's air polygons wider than the flags (Caspian, Paracel). The jet circuit is 2.6 km, about 15 s at 170 m/s (bf3-vehicles.md §6.12).

The full BF4 level table, computed from maps.json for all 31 levels, is on BF4 reference: maps.