He will always aim at the center of a building. This means he will not take advantage of the Artillery's ability to equally damage multiple buildings, or the ability of the Shock Bomb to shock four adjacent defenses in a line.
He will always target the same building(s) with Gunboat Weaponry on successive attempts of the same stage. This means that after your first attempt of a stage, you can move the targeted buildings aside so that the Gunboat Weaponry does not affect your other buildings. However, if said building(s) is/are destroyed by his attack before Hammerman can target them, Hammerman will attack a different building instead.
He uses Gunboat Weaponry at the beginning of each wave while deploying troops; he will not support troops with Gunboat Weaponry until he deploys his next wave of troops.
The troop deployment locations for a stage are fixed. This means that if you retry a stage, he will deploy each wave of troops in the same place that he did last time.
Hammerman will use troops of all different kinds except Cryoneers. Hammerman can only deploy a certain maximum number of Landing Crafts for each troop type except for Riflemen. Notable examples include:
Scorchers, of which he will deploy at most one (using one Landing Craft)
Tanks and Medics, for which he will deploy at most three Landing Crafts each
Grenadiers, which he will deploy a maximum of eight Landing Crafts
For you to win, you must either defeat all of the troops that Hammerman deploys or keep your Headquarters safe until time runs out.
If you fail a defense but defeated part of the troops in one try, these defeated troops come back in the next try, so it is all or nothing.
General insight is the player's best chance at surviving a wave. When toggling Hammerman's Gunboat to initiate an attack, be sure to preview the Troops he plans to bring along with him, and their order from left to right.
Troops that are dropped off first can be planned for, such if Hammerman chooses to load off an entire wave of Zookas first, it would be best to place splash damage defenses such as Rocket Launchers and Mortars so their range intersects with the beach.
Rifleman swarming is a pretty popular tactic of Hammerman's, and it is very difficult to deal with, especially when Medics are a part of the equation. Wherever one plans to eliminate hoards of Riflemen altogether, place a neat and organized row of Mines in their path. The multiple continuous strikes are not likely to be healed before the Riflemen die.
Hot Pots are extremely effective as their great damage per second will easily counter any Medics' healing, and eliminate large amounts of Riflemen within seconds.
If Hammerman decides to deploy a wave of Grenadiers ahead of all other combinations, it is best to throw every Boom Cannon and a Shock Launcher, coupled with a few Sniper Towers at the beach head. If the player feels the next wave will be a hoard of Riflemen, plop these long range defenses nine to eleven tiles away from the shore and place Boom Mines at the head of the beach instead.
A Shock Blaster is extremely effective at dealing with Grenadiers. Their high damage per second, combined with their long range, can easily shut down a wave of Grenadiers.
Take advantage of Hammerman's AI. If you spy him Barraging a defense of your's down, put it off to the side in the next attack and rid any mines away from its proximity.
One could take advantage of this knowledge and place it in a position where it is likely Hammerman will use his GBE on it when his Troops pass around the targeted building. This is especially useful when clearing an unstoppable swarm of Riflemen.
In the case of a Warrior rush right off the bat, sacrifice any economy building (usually one to three for the lower stages) in their path. If Riflemen do not follow, place regular Mines around the front of the bait buildings. Warriors should not make it to the second line.
To take advantage of any strategy of Hammerman's, maximize the amount of time it takes him to clear all of your buildings and start aiming for the Headquarters. This is made easier to the player due to the fact that Lt. Hammerman does not use Flares.
This can be done with a variety of base layouts, but is particularly attainable with any variant of a sweep base, where all buildings create a wrap around the side of the base, follow to the rear of the island, and cycle back to the other side.
Notable features include a front line that begins at the shore of Hammerman's first chosen landing side on the beach and long range defenses such as Rocket Launchers and various Prototype Defenses placed in the center of the island.
If you have attempted to defend Hammerman and failed, but know that a lot of Riflemen were left at the end of the attack, you could place a line of Mines at the back, behind most of your defenses but in front of the HQ. Be sure to redirect the remaining Riflemen in a manner such that they would move to the next building in the formation of a line to maximize the effectiveness of this strategy.
One of the most effective formations for these Mines would be a checkerboard pattern; the Mines at the back will finish off the Riflemen that are heavily damaged from the first impact.
Placing a spare Boom Cannon next to the HQ in that case could be critical to the success of a defense. If a few Riflemen survive the line of Mines, the Boom Cannon can pick them off one by one before any more damage could be done. The Boom Cannon is also integral if the player wishes to stop Tanks that may have been protected by the mass of Riflemen.
The strategy may be less effective if Hammerman uses Critters on your main defense on the last wave. If your defenses are heavily crippled and he starts his fourth wave while placing Critters in the area of your main defense, the Critters could move in front of the Riflemen and trigger some of the Mines, which were critical to defeat the mass of Riflemen in the first place. The same is true if his last wave contains Warriors or other fast troops.
If the layout is poor, Grenadiers may render the strategy ineffective if they manage to hit the Mines while attempting to hit a building in front of the Mines. To avoid this, ensure that the distance between the last line of the main defense and the line of Mines is as large as possible.
Damage Amplifiers are a great supporting Prototype Defense for defending Lt. Hammerman, especially if you do not have Defensive Building Damage Ice Statues. You can use it to increase the damage output of a large portion of your defense, thereby allowing them to eliminate Hammerman's units quickly.
The best defenses to put under influence of a Damage Amplifier would be Rocket Launchers, Shock Launchers and Boom Cannons. Amplifying the former two allows you to stop Riflemen and Zookas quickly while amplifying the latter can quickly take out Tanks and Scorchers. Another good choice would be to amplify a high-damage Prototype Defense, such as a Shock Blaster or Hot Pot.
Understand when to stop initiating attacks. If the player struggles but manages to wipe out Hammerman's attempt at 4, and at stage 5 the player is absolutely obliterated, it is highly unlikely that any formation of the base is capable of defeating the stage. Wasting Gold needlessly is not in the player's interest.
Hammerman's attacks do not count toward the Strategist Achievement. They instead count toward the Hammer Down Achievement.
Similarly, his attacks will not be counted as attacks or raids (or both) in the "Daily Summary" part of the Activity Log.
There's an achievement which is called Hammer Down that gives a total of 175 diamonds upon victoriously defending against a total of 40,000 troops in the Hammerman Strikes Back event.
Note that this achievement counts the number of troops, not the housing spaces of troops. Even one scorcher counts as one.
The number of troops are counted by the ones that are deployed, not the ones that you killed. If you win by time out, you're still awarded the full number of troops deployed.
The criteria of this achievement are incorrectly translated in several language settings of the game.