Nightmare difficulty was introduced in patch 7.13. It is the highest difficulty level available in Dungeon Defenders. While not yet generally available, players who have bought the Quest for the Lost Eternia Shards Complete DLC on Steam can host maps on Nightmare. Any player may join these, regardless whether or not they bought the content.
Differences From Insane
The increase in difficulty from Insane to Nightmare is much greater than the from Hard to Insane. There are also several major differences from normal game play:
- Hero, tower, and pet stats are adjusted.
- Hero health and casting rate is scaled up, while hero damage is down scaled to ~1/6 and resistances to 2/3.
- Tower health and damage is scaled up, but some towers have reduced range; monk auras have 30% less range. Huntress traps deal 25% more damage.
- Pets are significantly more effective, notably melee pets such as the Mega Chicken.
- Hero weapon projectiles travel slower than usual.
- Spiders spawn at random locations (i.e. not necessarily coming from normal spawn doors, but dropping from above) on every wave on every level.
- Sharken and Djinn spawn at the normal spawn locations on all maps.
- Goblin Copters spawn at the same locations wyverns appear. They don't spawn on maps that lack wyverns.
- Ogres spawn much more often, and earlier than usual, such as Wave 1 on The Deeper Well. Heroes without significant upgrades to damage resistances on their armor equipment may find themselves killed in one hit. Ogres on nightmare also may have elemental resistances.
- Like Insane, the Build Phases have time limits on Nightmare. Familiarize yourself with the map's layout before attempting it on either difficulty.
- If you're first starting to play maps on Nightmare, look into Hero Shops to buy cheap Mythical items. Sometimes you can find a piece of gear for 1-2 million Mana, and it will pay for itself once you get Mythical loot dropping for you!
- Remember that you get a set bonus for wearing all armor pieces of the same type (Leather, Mail, Chain, Plate or Pristine). For Godly quality armor and below, the set bonus is +25% to all stats given. Armor of Mythical quality or higher get higher stat bonuses, but all equipped pieces must be at least Mythical to get any set bonus at all.
- If ogres are problematic for you, focus on single-target towers and walls. A squire with a high block value can tank the ogre while your towers kill it very easily. Note that elemental towers may be ineffective against an ogre if it's of the same type, so don't overload on elemental damage without some way to remove affinities.
- If you are dying too much, prioritize upgrading your resistances over hero health. Having 45% physical resistance will allow you to last almost twice as long in nightmare, which is more effective than spending armor upgrade levels on Hero Health.
- Cover your towers. A brilliant defense means nothing if it gets webbed by spiders. Your defense should be as close to the crystal as possible, to minimize the chance of spiders spawning behind it. However, always have towers pointed inwards to deal with spiders, as they seem to love spawning on your crystal(s).
- Wyverns fly a lot faster than normal. Make sure your towers have sufficient range and attack rate. You could sometimes need some extra defenses to handle wyverns (additional offensive tower, Ensnare Aura, or even Darkness Trap along with Ensnare Aura).
- Distract ogres. Having three ogres smashing your defenses is better than four. Simply move behind them within melee range (even if you're ranged) and attack them. This should get their attention and turn around. You'll have enough time to get out of melee range of the ogre, but don't go too far or they'll lose interest and head to the crystal as normal. If you lose the attention of an ogre for any reason, get within melee range again and attack. This should get him to focus on you again.
- The Apprentice Guardian and Huntress Guardian familiars will be very useful and assist your towers greatly. The towers that it buffs can easily do more than twice their damage. Even the Hard summit reward pets are worth their weight in gold, and will contribute more to overall DPS than any DPS pet.
- Endless Spires is a good map to start playing Nightmare as there is lots of room to kite the ogre in the first wave.
- "Chaos" replaces Nightmare difficulty in Dungeon Defenders 2 which has different mechanics.