When certain GB's get to a high enough level, they have profits in the first place reward for those with Level 80 Arc, from the moment the level is opened - sometimes referred to as the "Arc Magic" level. Below are the common GB's taken to high levels and at what level Arc Magic (profit at 1.9) starts:
Arc - Level 30
Inno Tower - Level 30
Cape - Level 33
Alcatraz - Level 36 (wiki says 38)
AO Snowflake - Level 38
Château - Level 36 (wiki says 38)
Zeus - Level 38
Aachen - Level 39
Terracotta - Level 39 (wiki says 35)
CDM - Level 40
The Arc (Future)
It's not a sniper unless they have a level 80 arc and secured a spot on your GB at less than 1.9 value. A lot of people are confused about the term "sniper" on GB's thinking it means anyone who adds to your GB without you asking them, or by getting your permission first. Permission has nothing to do with it, you don't need to sign the Magna Carta first to be able to add to someone's GB's, the game allows it and as long as there's no malicious intent, what's the problem?
The term sniper is all about people who undercut the value of a spot on a GB deliberately in order to make profits for themselves. There is malicious intent and these people often have level 100 arcs or higher and are in it for whatever profits they can gain, paying in much less than 1.9 and making much more than 1.9 in return. How to avoid snipers is covered more in the next section, but once your GB reaches profitable levels at 1.9 (level 30 and up on most GB's, see list below) then you need to open 1 blueprint level at a time and ask the guild to take the profitable spots right away before they get "sniped."
Things that are not sniping:
When you put less on a spot because someone "overcooked" it i.e. you have to take profit because there's no room to put full value
Poor guys in your hood/friends who add random amounts to your GB, just trying to get a few blueprints and medals
An important strategy note for everyone - do not unlock blueprint sets past around level 30 on most GB's, especially the Arc! Once you get to the 1.9 profitable levels of each GB, you need to unlock one level at a time and try to get guildmates or very good friends on 1st and 2nd right away so that you don't get sniped for 100's of profit by enemies or opportunistic hoodies.
If you do open past level 30, especially on Arc, it's going to get sniped for hundreds every level and rolled for profits once you reach those profitable levels. If you open blueprint sets too far ahead, you will lose control of your GB and people will level it up early, without letting you double collect, just to snipe first on the next level for the profit (i.e. it's worth it to a sniper to finish the last 50 fps on your previous level, if you have the next level unlocked already and they can make 200 fps sniping first on the next level.)
Usually only spots 1-2 are ready at 1.9 when the level opens. A few levels of some GB's can lock 1-3 from the minute they open, and those are the most dangerous levels to get filled before they are sniped, since they have so much profit available. Most of the time though, the owner has to add some fps after 1 and 2 are on, before the 3rd spot can be locked at 1.9.
The wiki fan page for the Arc has a table of all GB's and when Arc Magic (profit at 1.9) starts and stops for each: https://forgeofempires.fandom.com/wiki/The_Arc
Here we include only those most commonly raised above level 30.
We have a thread for those with high arcs to help those trying to raise Arcs (and other GB's).
When you post your GB it should have room to "lock" our spot at 1.9x the FP return when we contribute fps so that we cannot be overtaken from the spot. Level 80 arcs return the FP reward X 1.9. Usually a GB has to reach a high enough level to start making profits from the minute a level is opened, on Arcs this is level 30, for Traz its around level 36 (sometimes referred to as "arc magic" level.)
If your GB has profit from the minute the level is unlocked, you should only unlock 1 set of blueprints at a time (from level 30ish on most GB's you should do it this way) and try to get someone here before you open the level, or it will get sniped for profit as high Arcs are everywhere in the game now.
Otherwise you need to add FPs yourself until the math is right for 1.9x to work. Don't use chains for this or it messes up the math to have someone sitting with 100 fps on it when we go to take 1st or 2nd, it needs to be your 100 fps or additional may be needed to secure the spot from whoever is already on the GB. It's your guarantee that spots posted/taken for free with Arc 1.9x won't be sniped and you're responsible for losses if they are. Everyone should CALL OUT SPOTS before you just add to avoid crashes when 2 people go for the same spot at the same time.
If you're going to take spots and don't have a level 80 arc, you'll have to put more in than the reward returns. If you want the spot for medals and bps that's fine, but still needs to be the 1.9x FP return amount regardless of your personal arc boost return.
If you need help calculating the 1.9 amounts, try the website GB calculator: foe.tools/gb-investment/
Power leveling needs 6 people per session to swap roles among the following:
1 who can open levels of their GB and keep adding owner contribution
4 with high arcs to put 1.9 on spots 1-4
1 who can take 5th position with or without a level 80 arc (low cost)
Use the guild chat so as not to spam threads; it works really well if everyone is assigned a spot and takes the same spot every level so that it's not being called every time or waiting; if you're taking 3rd you keep taking 3rd every level. If you need more medals or blueprints, sign up to take one of the top spots before we start.
The person who is getting their GB power-leveled has to have the FPs to add their part and tell us in chat as each new level is open to be filled. It will be too expensive to power level if you aren't close to level 30 or the profitable levels for 1.9 help - basically if you would not put the GB onto the 1.9 thread because it is too low, it's not a good candidate for power leveling. Also anything that requires you to use 'charges' each day is not a good candidate (Kraken, Blue galaxy, Himeji, Space Carrier, Truce Tower, Voyager) as you would just waste all the charges by leveling quickly and not using them.
A good session takes a few minutes to setup, you need to be online about 30 minutes (or longer, if we want to get through more GB's.) It also takes some patience to get a group together, but once we get going we can do 1 level per minute.