  Template:Wad Stronghold: On the Edge of Chaos is a Doom megawad, created by Daniel "Tormentor667" Gimmer and his team at DRD Team and Realm 667. It requires GZDoom or Skulltag to run. Supports both singleplayer and multiplayer. There were two release candidate versions in August 15 and October 15 respectively, with the final release now available.
Official description:
You know Doom, it is always the same, get some weapons, infiltrate the destroyed UAC base or demon hive, kill all the monsters and hellspawn and find the exit switch. This was Doom... until now: Stronghold is a mixture of Unreal Tournament's Assault mode and Skulltag's Invasion mode. Defend your Stronghold against hundreds of monsters, divided into several waves. Earn points, get rewards between waves and let no single enemy pass!
Features:
- 35 new maps (+4 secret maps)
- 18 powerful weapons
- 20 different powerups
- 30 additional new monsters (in addition to original ones)
- Several different game modes (Deadline, Core, Limit and more...)
- Full multiplayer support with Skulltag
- Earn credits for killing demons!
- Dynamic skill for all skill settings and player counts
- Hub system with several tiers to battle through
- Shop system with countless items to buy
- Full soundtrack with exclusive music and songs
- And many more thing to discover!
Stronghold is a dooming experience that's very different from what usual Doomers might have played so far, and it really deserves a try, especially the multiplayer coop mode for which the team have worked so hard to balance it. The game is one huge hub with 35 different Stronghold UAC bases that players need to defend, where there are different goals to achieve (e.g. let no single enemy pass the deadline or defend a powercore agains the demons). For support, there is a huge arsenal of weapons and powerup items players can collect and/or buy in the interactive intermission base from where they start their missions. The new approach towards the legions of demons and also the countless gimmicks, specials and easter eggs will make up for a very unique Dooming experience.
Gameplay
Stronghold is a defensive game, somewhat like a first-person shooter version of a tower defense. Players are tasked with defending a variety of bases from waves of approaching demons. Most levels have ten waves; as the waves progress, more monsters spawn, but better weapons and powerups become available.
The game is partially mercenary in style - players have some control over what order they do the missions in, and are paid credits for each kill as well as a large bonus for completing each mission. Credits can be spent at the Hub to purchase a variety of weapons and powerups. Some notable items are the Marine, which spawns a single AI-controlled marine to assist the player, and the sentry turret, a powerful and heavily armored automatic turret. Players can also buy health and armor upgrades, invulnerability, the chronosphere, and more. Items can be used in missions or dropped for other players to pick up.
Although players can purchase items and powerups between missions, they cannot purchase weapons (aside from an item that gives a random weapon when activated). Players begin each mission with the pistol, but new weapons become available on spawnpads as the waves progress, the same as Skulltag's Invasion mode. Different weapons are available on each mission, although the shotgun and chaingun are always available.
Once a mission has been completed, it remains available for replay, but now in time attack mode - the player must rapidly kill all the monsters to launch the waves more quickly and beat all ten waves in the time limit. This requires extensive usage of the items.
If killed during a mission, the player can respawn as long as he or she has at least one remaining life in his or her inventory. Players start with three lives, and can purchase more over the course of the game, although they are extremely expensive. Players can also drop lives to give to deceased teammates with no lives remaining so they can respawn.
Gameplay modes
- Deadline - The demons are approaching a portal, called a deadline, in the back of the stronghold. If even one demon reaches the deadline, the mission fails.
- Core - A computer core located at the back of the stronghold is the target in this mode. The core has health, and monsters will attack it until it is destroyed.
- Milestone - Similar to Deadline, but the level is an elongated path with checkpoints called milestones along the path. Once a single demon has crossed a milestone, all monsters spawn from that milestone until another milestone is reached.
- Limit - Also functionally similar to Deadline, but rather than failing when a single monster reaches the endpoint, a large number can pass through until the limit is reached.
- Overlord - A massive demon called the Overlord attacks the Stronghold, attempting to destroy all of a series of nodes around the Stronghold. In addition to the Overlord, monsters spawn in waves as normal, but new waves are triggered with every 10% health the Overlord loses.
- Goal - Several targets with limited health are located throughout the Stronghold. The demons will spread out and destroy the targets. If all targets are destroyed, the mission is failed.
The lost soul is a massive threat in most of these game modes because of its insane speed meaning they will be the main focus whenever a wave occurs that has these demons or pain elementals in them.
The Hub
The Hub is the central area the player is sent to between missions. There are several shops which sell different kinds of items, and many NPCs walking around the facility. Some NPCs can engage in dialog with the player; they will either give gameplay advice or offer the player simple quests related to finding items in the Hub or on missions.
Throughout the Hub are many large doors leading to missions. The player can approach a door to read about the location and find out what the payout for completing the mission is. Walking through the door will start the mission. Missions are divided into tiers. Each time a tier is unlocked, some of the missions in that tier will be available immediately, while others require several missions to be beaten before being unlocked. There are 3 secret mission that require one to have a keycard or knowledge of a code to enter. These are completely optional. One of them those that played doom for a long time will recognize immediately.
Spoiler alert if one does not want to know what this hidden mission is don't read!
The hidden mission its map layout is a redesign of E1M8 from the ultimate doom.
When one completes all tiers they will have to find and talk to a certain scientist that says they've seen a massive demon that apparently easily destroyed a base. At the end of the conversation the Hub gets attacked beginning the last mission of the modpack.
New weapons and Items
This modpack has the flamethrower and repeater in it plus some additional weapons.
Scorch cannon: Essentially the upgraded version of the flamethrower it uses the same ammo as it but fires a massive fireball that explodes dealing massive damage to enemies that get caught in it.
Proximity mines: These mines will explode when an enemy gets close enough to one. Its great for dealing with suicide bombers and certain other enemies but it won't work well against some of the more powerful demons or ones that fly.]
Auto shotgun: This is one of the less useful weapons in the mod because of how late it shows up when it is outclassed by other weapons. It is apparently the only weapon in the mod I believe that uses actual clips so shells won't be depleted until it has to reload.
Annilator(?): The most powerful weapon in the mod this weapon easily puts the BFG to shame with how much damage it does but its more risky to use because of the fact that it can also damage players as well.
Bruiser sphere (What I think its called): This sphere when used transforms the one who uses it into a bruiser demon being able to use a bruiser demons attacks for a certain amount of time.
Turret sphere: When used it deploys a turret that fires on enemies when they get close enough. It has a life bar meaning it won't vanish until it is destroyed.
Vampire sphere: This sphere when it is activated gives the player's weapons a drain life effect which means if they constantly deal enough damage they can be invincible.
Helmet sphere: This sphere is pretty much a portable invulnerability. I call it that because it has what looks like a helmet on the front.
Power sphere: When activated this sphere behaves just like a blood sphere meaning the player will deal more damage then usual.
Nuke sphere: This sphere has a radioactive symbol on it and it pretty much kills most enemies that have spawned instantly. Only a select few enemies can survive the punishment.
Marine sphere: This sphere summons a marine that will have a random weapon equipped when used.
These are just some of the weapons and items that are included in the mudpack.
Editing
Stronghold also supports user-made custom map creation. Doom Builder 2 is recommended for map editing for Stronghold, as it has more features than Doom Builder 1.
New enemies
Suicide bombers: These guys will start showing up at the last level of the 1st tier and you can guess these guys are kamikazes. They will pretty much run to what you are trying to protect. When killed they will explode dealing damage to those right next to them.
Zombies driving mechs: In the final level overall you will see some zombies that apparently are using mechs since you will be unlikely to have a good weapon to deal with them unless you used the random weapon sphere you can buy from the shop and got a good one from there, these guys will be very hard to deal with.
Overmind: The final boss of Stronghold on the Edge of Chaos this guy is not to be underestimated he will appear at the last wave of the final level. If one is trying to do this megawad solo they will likely be forced to cheat once this demon shows up due to the insane damage he can dish out.
These are just some of the new enemies in the wad.