In Infinity Kingdom, players only gain Honor Point to increase the Nobility Rank by defeating other lord’s troops.
So attacking a castle gives nothing most of the time unless they are garrisoned and if someone doesn’t want to fight in their castle there is no way to force them to.
That said there are a few ways to get the honor points.
How to get Honor Point for Nobility in Infinity Kingdom
Attacking Resource Camps
You can attack resource gathering camps that enemies are at. Move right beside the node before attacking to avoid the player getting a notification.
You can do this by sending your March to a nearby location, and then once close, redirect to the enemy rss camp
Lots of players are also looking for fights to trade honor until hospitals are full, find a comparable power player and agree to meet up somewhere for one vs one battles where you take turns attacking. If you don’t count travel time, or can plan regularly scheduled battles this will give the most consistent time-efficient honor
Warring vs another alliance will result in a lot of Honor for all participating members. If you start losing you will gain lots of honor, but if your hospital fills, you may have to go Defensive to avoid excess casualties which lowers prosperity, and may random teleport you away if you keep getting attacked.
One trick to hide your power level, is removing team B and C immortals from your lineup. You can reduce your power on the world map by almost 20k. If the enemy sees a low power level they may be more likely to attack you.
Infinity Kingdom Nobility System
1. Defeat other Lords’ Troops to gain Honor and increase your Nobility rank.
2. Nobility grants attribute bonuses to all your Troops.
3. Some Nobility ranks have player quotas or are restricted by Lord level.
4. Nobility ranks with player quotas will be reallocated every Sunday at midnight UTC.
5. Higher Nobility ranks deduct 1% of your current Honor every day.