- +10% National tax modifier
- +2% Missionary strength
- +1 Diplomatic reputation
- +2 Tolerance of the true faith
- +15% Improve relations
- +10% Trade efficiency
- +10% Provincial trade power modifier
- +25% Fort defense
- −10% Ship cost
- +1 Missionary
As a free city, Bremen is protected by the Emperor at the beginning of the game. As the player's goal will probably be to grow as fast as possible, they'll lose this protection early into the game. Bremen is quite weak but still richer than some of its OPM-neighbors. Finding allies is a good starting path. Due to its size, Bremen won't be able to immediately ally great regional powers like Brandenburg or Bohemia. Allying Hamburg and Lübeck may be a good choice if these OPM rival the player's enemies.
A recommended first move would be to fabricate a claim on East Frisia and to annex it, as it is the only OPM around you that does not belong to the HRE and thus will result in lower aggressive expansion and the Emperor won't demand to return unlawful territory. Adding this province to the HRE can boost your relations with the emperor as well. Taking East Frisia will also give you a trade bonus, as it is the location of the Ems estuary.
If Denmark doesn't ally a great power like Poland or Bohemia, it is recommended to fabricate claims on their territory: Sweden's declaration of independence creates a window of opportunity to expand in Scandinavia, if Sweden has under 50% liberty desire, they well help Denmark, so it is not recommended to attack.
Abandoning your first government type
Once the player has grown enough, they'll face a huge challenge: the emperor will have high Aggressive Expansion and possibly even Unlawful territory penalties due to the player's fast expansion within the HRE, and the player's enemies may be allied to great powers like France or the Commonwealth which refuse to ally the player because the player are still too small or because they are already allied to the player's rivals.
From there, it should be envisaged to change the player's government type, as the republican system affects your safety. Although the player is not powerful enough to ally great powers, they can improve relations with them in order to contract royal marriages and prevent them from attacking the player or from joining wars against you. For instance, if the Netherlands have rivaled the player and are allied to France, they cannot call their ally to arms if you contracted a royal marriage with their ally.
The fastest way to abandon the republican system is to re-elect the current ruler until they declare the country a republican dictatorship (requires Res Publica). When the ruler dies, the country will become a monarchy which allows it to contract marriages with other states.
Colonizing the new world is not really recommended, although it is possible. At first the player will need to wait until higher diplomatic technology is reached in order to have a sufficient colonial range to reach America or Africa. That means that other colonial powers will be a step ahead of the player. Furthermore, the trade generated by the player's colonies cannot be transferred to their home trade node unless the player has good control over the English Channel and/or Sevilla nodes. It may be better to save the player's diplomatic points to increase your diplomatic reputation. In reality, Germany didn't enter the colonial race until the late 19th century.