Intent: Give defender control over defense timings, enabling defender to bring in fleets against attackers. Improve defender outcomes when it comes to active versus inactive players. Shifts defense emphasis from static ODS / barracks to time distortion and fleets.
Problem With Feature: Easier defense leads to game balance issues.
Mechanic: “Time Distortion field” building triggers when enemy fleet attempts to enter planetary orbit. Instead of entering planetary orbit, enemy fleet is locked in place for 9-24 hours during which ODSs etc do not fire as attacking fleet is not actually in planetary orbit yet. At end of period, enemy fleet enters planetary orbit and is subject to ODS fire &c. Attacker may exit time distortion field at any time by moving away from planetary orbit, including auto-movement (as in when a ship moves into planetary orbit momentarily then out of planetary orbit when moved around a planet).
Intended Gameplay: Online player waits for another player to go offline, sends bombing fleets &c. Attacker knows and controls attack timing, can be online when attacking fleets arrive at target, can decide whether to call off attack when interdiction field encountered. Offline player wakes up, logs in, notices attack, builds ODSs and/or sends fleets to wipe out attackers.
If attacker is online and notices fleets incoming or ODS buildup, they can run away. If online player went offline, probably their attacking fleets get wiped out, that’s the risk they take.
Comments: Fleets can move away from threatened areas, planets cannot. ODS and barracks-based defenses are static and boring and costly. When offline player is attacked, defending fleets sit around uselessly as attacker scouts ahead to go where defending fleets are not.
Time distortion for planetary orbit means one fleet can protect more than one planet, freeing fleets to be used elsewhere, increasing player options.
Locking attackers without ability to back out increases attacker risk, reducing attacks, leading to conservative gameplay. Game mechanics should encourage players to do things and move around.
[EDIT 1]: Changed “Warp Interdiction” to “Time Distortion” field. There is no warp in a planetary system (thank you Puma), and “time distortion” is a better reference for the feature anyways. Future edit to address attacker needing to sit on top of fleets, other things as I read through posts.