View source for Decoys

'''Decoys''' are consumable defenses against incoming torpedoes and missiles. The launch message describes a device moving away while transmitting a ship-like sensor signature, but the simulation stores each active decoy as a timer slot on the defending ship. A decoy has no independent position, heading, speed, or scan-table entry. [[Decoy command]] covers how to deploy one and the launcher restrictions.

== Interception ==
Each main ship-state update, normally about six seconds apart, active decoys are tested against eligible incoming weapons still in flight. A torpedo must be ''less than'' 5,000 distance units away; a missile must be ''less than'' 3,000. A weapon close enough to resolve its impact on that update hits before the decoy checks. Otherwise the game tests the defender's active decoys in slot order; the first successful decoy destroys both itself and the incoming weapon, so later decoys are not tested against that weapon.

Each eligible decoy gets a separate one-in-<code>DECODDS</code> chance. The stock <code>DECODDS</code> is 11 in both classic and ge-next, giving the following chance of intercepting ''one eligible weapon on one update'':

<syntaxhighlight lang="text">
chance with N decoys = 1 - ((DECODDS - 1) / DECODDS)^N
</syntaxhighlight>

{| class="wikitable"
! Active decoys !! Approximate interception chance
|-
| 1 || 9.1%
|-
| 2 || 17.4%
|-
| 5 || 37.9%
|-
| 10 || 61.4%
|}

These are per-update chances, not guarantees for the whole flight. A slower weapon that remains within interception range for several updates can face further rolls. Lowering <code>DECODDS</code> increases effectiveness; at 1, the first active decoy always intercepts an eligible weapon. Decoys offer no protection from phasers, mines, ion cannons, collisions, or self-destruct blasts.

Classic notifies the defending player when a decoy intercepts a weapon. Since ge-next 0.2, an active user who fired the intercepted torpedo or missile also receives a lost-to-decoy notice. This is a notification change, not a change in the interception roll.

== Lifetime and expiration ==
A launched decoy starts with a timer of 15 ship-state updates. In classic, each update reduces that timer, and reaching zero self-destructs the decoy. At the actual six-second update interval, that is about 90 seconds; classic configuration comments describe the interval as five seconds. An intercepted decoy is removed at once and does not later print a self-destruct message.

ge-next changed expiration in stages:

# '''0.2.4:''' Decoys still expired independently on their normal update, but several expiring during the same update produced one batched self-destruct message rather than one message per decoy. Their lifetimes did not change.
# '''Early 0.3:''' A one-update launcher reload delay meant normally launched decoys could not start with identical timers. The earlier same-update message batching became largely pointless in ordinary play.
# '''Later 0.3:''' A shared expiration pass was added. A timer that reaches its final value waits there until this pass; all waiting decoys can then self-destruct together and use the batched message. The pass occurs once every five ship-state updates, so a decoy may last up to about 24 seconds beyond its base lifetime.

A ship can have at most ten active decoys. In ge-next, [[Report command|<code>REPORT ORDNANCE</code>]] shows the number deployed. NPCs with decoy capability may also launch them; their decoys use the same interception and timer rules.

== Scope and travel ==
Decoys are local defenses attached to the ship, not independent objects a player can place in a sector or steer toward a projectile. They cannot be deployed in hyperspace, and entering hyperspace clears those already deployed. They are not a general defense against weapons other than inbound torpedoes and missiles.

== See also ==
* [[Decoy command]]
* [[Torpedoes]]
* [[Missiles]]
* [[Report command]]

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