Guide

Game post-plant retake timing and geometry systems explained

Harbor Siege's ranked map Siege Yard shipped with a B-site that looked fine in blockout playtests: two chokepoints, a default plant behind crates, vertical cover. But once ranked economy and defuse kits entered the loop, defenders on the CT spawn could not reach the site, clear a post-plant hold, and start a defuse channel before the 40-second fuse expired — even running with a kit. Players filed “unwinnable retake” reports on 58% of B-site plants. Attackers learned to force B every pistol round because the round was effectively over at plant. The problem was not the fuse timer alone; it was the gap between geometry (travel distance, choke width, vertical layers) and timing budgets (fuse, defuse channel, utility fade).

Post-plant retake design is the discipline of making defender comebacks mathematically possible without making plants free wins. It couples map layout, spawn routing, objective FSM state, and equipment tiers into one fairness equation. Harbor Siege shortened the CT rotation path to B by eight meters, widened a retake choke by one player-width, and added a server-side retake_window telemetry field so designers could see when fuse math broke. Unwinnable-retake reports on B fell from 58% to 12% while A-site tension stayed unchanged. This guide covers fuse vs travel-time budgets, site geometry patterns, defender routing, the retake FSM, utility timing windows, audio telegraphs, the Harbor refactor, a decision table versus timer-only tuning, pitfalls, and a production checklist tied to bomb plant rules and smoke vision systems.

Why post-plant geometry is a separate design problem

Opening-round geometry optimizes for attacker entry timing and defender anchor positions. Post-plant geometry optimizes for retake feasibility once the round clock becomes a fuse. The same site can feel balanced at 1:40 remaining and broken at 0:25 after plant because:

Defenders must travel from spawn or a lost flank — not from pre- positioned anchors.
Attackers control utility timing: post-plant molotovs on defuse points, one-way smokes on chokes.
Defuse channels are interruptible; retake time must include contest, not just running.
Economy affects kit ownership — retake math must work for both kit and no-kit defenders on average rounds.

Treat post-plant as a first-class validation pass, not an afterthought on top of entry routes.

The retake timing equation

At minimum, designers need this inequality to hold for a fair site on average competitive loadouts:

fuse_remaining >= travel_time + clear_time + defuse_channel + safety_margin

Where:

travel_time — server-measured path from defender spawn (or last known rotation point) to plant volume edge at sprint speed, including door interactions.
clear_time — expected seconds to trade one anchored attacker or force a reposition; typically 3–8 s in ranked tuning, not zero.
defuse_channel — 5–10 s bare hands vs 3–5 s with kit per your defuse equipment rules.
safety_margin — 2–4 s buffer for net jitter, partial utility, and human reaction.

Harbor Siege's broken B-site failed because travel_time + clear_time + defuse_kit averaged 41 s against a 40 s fuse when defenders rotated from CT spawn. Attackers did not need to shoot — they only needed to plant default and watch the timer.

Build an automated retake budget report per site: for each defender spawn cluster, compute shortest navmesh path to each plant anchor at max move speed; flag any path where budget exceeds fuse minus margin.

Site geometry patterns that affect retakes

Layout choices change clear_time more than travel_time:

Single-anchor default plants — predictable defuse spot; attackers stack utility on one pixel. Good for readability; requires multiple retake entry lines so defenders are not funneled into one molly.
Multi-plant volumes within one site — raises attacker flexibility; defenders need audio triangulation. Retake math must use worst-case plant point for travel budget.
Vertical sites — ladders and ropes add animation lock time not captured by flat navmesh distance. Add vertical_penalty to travel_time.
Long sightline anchors — OP angles after plant inflate clear_time; pair with flanking routes or destructible cover.
Narrow retake chokes — one-player-wide doors let a single incendiary deny the entire retake window; widen or add parallel breaches.

Siege Yard B's fix was geometric, not numeric: a side breach route cut travel_time by ~2.5 s and let defenders pinch from two angles, reducing clear_time against single-anchor holds.

Defender spawn routing and rotation telegraph

After plant, the server should know each defender's retake ETA based on position, not just spawn assignment:

Spawn-to-site tables — precomputed paths per spawn cluster and site; used for fairness QA and spectator overlays.
Mid-round position — a lurker on the wrong map half may be closer than rotating spawns; retake calls should use live distance, not role fantasy.
Rotation audio — footsteps on metal grates during retake flanks are intentional tension; do not over-attenuate if you want trade skill.
Spectator retake timer — broadcast overlays showing “earliest possible defuse start” help esports viewers understand whether a retake is live.

Avoid spawning all defenders at one far cluster when the planted site is on the opposite end unless fuse math explicitly accounts for a longer fuse on that site — asymmetric fuse lengths are valid but must be documented in the pre-match rules panel.

Post-plant retake FSM

Server-authoritative retake phases keep clients aligned on what actions are legal:

PLANTED — fuse ticking; attackers in post-plant economy lock (no buy); defenders en route. Utility from both sides resolves under post-plant rules.
CONTACT — first defender enters site volume or line-of-sight to plant; attacker hold becomes active contest.
CLEAR — no living attackers in site volume (or within plant deny radius); defuse channel may begin.
DEFUSE_CHANNEL — interruptible channel; damage, movement beyond threshold, or attacker re-entry cancels progress.
RESOLVED — defuse complete, detonation, or round time expiry.

Expose FSM state to minimap and kill feed systems so players understand why a defuse paused mid-channel. Replays should stamp FSM transitions for dispute review.

Utility timing windows after plant

Post-plant utility is asymmetric: attackers know plant location; defenders must clear blind. Design explicit durations:

Post-plant smoke on defuse spot — if smoke lasts longer than remaining fuse minus defuse_channel, the round is unwinnable without wallbang RNG. Cap overlap or allow short “defuse vision” cues after smoke fade starts.
Molotov on bomb — denies channel while fire ticks; pair with kit speed so a defender who wins the duel still has seconds to defuse after fire ends.
Flash timing — defenders flashing in need follow-up time; attacker blind duration should not exceed typical peek-trade window without counterplay.
Utility decay on planter death — some titles reduce post-plant denial when the planter dies to reward picks; tune carefully to avoid punishing successful plants.

Harbor Siege added a server flag utility_blocks_defuse on area effects so QA could measure how often molotov+smoke stacks removed the entire retake window on Siege Yard B before the geometry fix.

Audio and visual plant telegraphs

Defenders rotate faster when they trust plant call accuracy:

Global plant sting — distinct from round start; stereo pan hints site side without revealing exact corner.
Site-specific VO — “Planting A” vs generic beep; reduces wrong-site rotations that waste travel budget.
Carrier minimap pulse — optional ranked setting; shows bomb carrier until plant completes, then switches to planted icon only.
Fuse UI — visible to all players; defenders plan retake off remaining fuse, not round clock.

Telegraphs must match plant channel rules — if plant audio is audible globally, attackers cannot silent-plant without a suppressor mechanic.

Harbor Siege refactor (Siege Yard B)

Three changes, one telemetry loop:

Geometry — added breach route, widened retake choke, lowered default plant elevation so defenders arriving from ramp had line-of- sight trade angles.
Fuse policy — kept 40 s global fuse but documented that B's travel budget now targets 34 s worst-case to defuse start, leaving 6 s contest slack.
Telemetry — every ranked plant logs retake_window_sec = fuse_remaining at first defender site entry minus defuse_channel; dashboards flagged maps where p10 window < 0.

Unwinnable-retake reports dropped 58% to 12%. B-site pick rate rose from forced-default to strategic choice. A-site retake reports unchanged — proof the fix was local, not a global fuse buff that would nerf attacker plants everywhere.

Decision table: tuning levers vs geometry-first fixes

Approach	Best when	Avoid when
Shorten defender paths / add retake flanks	Travel_time dominates; site feels “too far”	Site is already cramped; widening creates attacker haven
Increase fuse duration globally	All sites on a map are slightly tight	Only one site broken — overbuffs other sites
Per-site asymmetric fuse	Deliberate layout asymmetry (A fast, B slow)	Players lack clear UI for different fuse lengths
Faster defuse kit channel	Contest time is healthy but channel too tight	Kit becomes mandatory; eco retakes impossible
Cap post-plant utility stack duration	Molotov+smoke removes all defuse seconds	Utility identity is the mode's skill expression
Timer-only changes without navmesh QA	Never — masks geometry debt	Always prefer measured travel budgets first

Common pitfalls

Playtesting with pre-planted bots only — skips travel_time from real spawns; always test full round-to-plant flow.
Using round clock instead of fuse for retake math — post-plant phase lengths differ; fuse is the authority.
Ignoring no-kit defenders — if only kit retakes work, eco rounds after plant are hopeless.
Single retake funnel — one door + one molly ends the round; parallel entries are mandatory on ranked sites.
Plant positions inside unpeekable corners — defenders must commit blind; add off-angle trades or sound cues.
Client-predicted defuse — desync on cancel; server owns channel progress.
No post-plant pause coupling — tactical timeouts that freeze bomb timer after plant create infinite delay; align with timeout freeze policy.
Clutch camera ignoring fuse — spectators think retake is live when fuse cannot mathematically allow defuse; show fuse on clutch overlays.

Production checklist

Compute navmesh travel_time from each defender spawn cluster to every plant anchor.
Validate retake inequality for kit and no-kit defuse_channel tiers.
Run worst-case utility stack test: smoke on bomb + molotov on choke.
Implement server retake FSM with CONTACT, CLEAR, and DEFUSE_CHANNEL states.
Log retake_window_sec and utility_blocks_defuse on every ranked plant.
Dashboard p10 retake window per site; alert when < 0 for two consecutive patches.
Playtest full rounds: entry, plant, rotate, retake — not isolated duels.
Document asymmetric fuse or site rules in pre-match UI.
Expose fuse remaining prominently; distinguish from round clock.
Verify plant audio telegraphs match competitive info policy.
Re-test after economy changes that affect kit purchase rates.
Include post-plant scenarios in map acceptance before ranked release.

Key takeaways

Post-plant fairness is a geometry + timing equation, not a single fuse knob.
Travel_time, clear_time, and defuse_channel must fit inside fuse with margin.
Retake FSM and telemetry make unwinnable sites measurable before players rage.
Utility stacks can erase retake windows even when paths are short.
Harbor Siege cut unwinnable-retake reports from 58% to 12% with routing geometry, not a global fuse buff.