Titans spawn from spawn point (sometime called "lanes"). They are two kind of spawn points : the off-maps one, signaled by a skull and an arrow, and on-site spawn point (volcanoes or toxic pools), signaled by fours arrows. The on-site spawn points usually only spawn the weakest type or titans.
A spawn points will alway spawn one type of basic titans in huge number, and most of the time will also spawn the associated leader titans in small quantities. The type of titans will not change if you retry the level with the same difficulty, so you can scout what spawn what, restart, and build your turret according to this information
The only exception are bosses. They spawn from a random off-maps spawn points, which will not spawn anything else. It mean you can't predict where the big one will appear, but with luck you can silence a particulary troublesome spawning point.
Non-leader titans dies when they attack a non-barricade buildings. Leader titans dies after 4 to 5 attacks against non-barricade buildings. In every case, attacking barricades cause no problem to titans.
You can place a non-barricade building on top of a titan to directly kill it. Your newly-spawned building will suffer some damage, however.
- Hit points : the number of damage a titan can withstand before dying. Wound before their death does not imped them in any way. Difficulty level can increase this value, up to three time the base value.
- Armor : the protection the titan have ; substracted from every damage source they take.
- Strength : when a titan attack a building, he remove his strength in damage point. The building collapse once it run out of HP.
- Speed : the movement speed of the titans. Some have specific speed patterns. The difficulty level increase the speed of the titans.
- Wgt : the weight of the titan, closely related to its HP and armor.
- Discovered : the first mission where you can find them in the main campaign. You may encounter them a little later depending on your technologies.
- Notes : specifics notes. The mosts commons are :
- Leader : will spawn along theirs lessers brethen in the same lane
- armored : have a significant armor value
- Boss : is a boss, spawn from a random lane and destroy base in one hit
- Spawn hatchling : will spawn miniature titans
- Hatchling : can only be dealt with by cluster mine, droids, or collateral damage. Not stopped by regular barricades (nanomesh will work, so do tangleweb)
- Ghost : Ignore regular barricade ; regular weapon will not target them unless you have X-Ray scanner ; capacitor will alway work fine.
- Flying : will ignore obstacles and can oly be attacked by lasers
- Armed : will attack your building with a ranged weapon
There is three type of titans behavior. It only change the way the titan choose its target ; for everything else the titans behave in the same fashion
- Stuborn : They target your base and only your base.
- Aggressive :They target the nearest building they see
- Smart : they target the most important building you have. "most important" seem to implie that limited-supplies turrets and refineries are targeted first.
In every case, they won't target an invisible building.
Once they have targeted a building, they will take the shortest route to the building, attack it, and once it's destroyed find another target. The shortest route don't take in account your building, but do take in account tangleweb (that slow them down), road (that speed them up).
They also take into account the danger posed by yours turrets, and try avoid them. The smallest turrets are never perceived as dangerous (that why you don't see titans avoid your turret before the moon), but blast cannon and heavy weapons will be avoided if possible.
The scarecrow work as if it were a very dangerous turret ; consequently, titans will try their best to avoid them. It won't help if the scarecrow itself is targeted (because the titans is aggressive or smart).
The inner working of the decoy is not know but it seem to make every titans in range target it instead of the regular target. It's not known if some titans (boss, for example) are immune.
The last thing that change their pathing - and one of the least understood - is collisions. Attacked titans are stunned for a little time (1/30 to 1/2 secondes) and consequently will slow down. Theirs brethen can't pass throught them, and will circle around the attacked titans. This can lead them to attacks barricades or turrets, and it's in fact the main attack reason in the early game.