The land claim system by placing building is flawed, and current suggestions like decay, or limiting claim by building sizes can inherently be worked around because it's always faster to build than wait for decay, or build a bit more stuff to block a spawn.
My suggestion would be to combine those suggestions to effectively protect the map against building spam, and rationalize the claim mechanic as a unique item per player.
My suggestion, in a nutshell would be something like this :
- Everyone is able to build anything everywhere, as is currently the case.
- Building in a non claimed area flag the building as unowned and can be destroyed by anyone with same tier weapons and/or decay very fast (won't last a day) and/or do not block spawnables around it.
- A new early tier item (flag, totem, something distinctive) allow players to claim a relatively small area. The claim extend upwards not to limit vertical buidlings, but is limited horizontally. The claim block spawnables around it.
- The claim protect your buildings around it from other players and decay. Players can still destroy them with weapons 2 tiers above like now.
- The flag is unique per player. You can upgrade it as you gain levels to extend slightly your claim zone.
- A clan can leverage multiple flags from clan members to build larger bases or bases at different locations.
- If a flag is deleted/destroyed, the owner has a set period of time to rebuild it before the base go back to unowned state.
- Building a flag over unowned buildings claims them.
- Makes better gameplay based on defending a limited amount of bases rather than a race to spam the map with foundations and pillars to block resources spawns.
- Encourages building up one base rather than spamming half assed outposts everywhere.
- Allows taking over enemy bases.