Relics are one of the most important progression systems in Universal Tower Defense, yet they are also one of the most misunderstood. Many players either equip random relics, waste gold upgrading the wrong ones, or completely ignore how powerful proper relic builds can be. When used correctly, relics can massively boost your units and completely change how they perform in difficult content.
This guide explains how relics work, how to obtain them, how upgrades and perks function, and how to build relics efficiently without wasting resources.
What Are Relics in Universal Tower Defense
Relics are equippable gear pieces that provide stat bonuses to your units. Every unit can equip up to three relics, allowing you to customize their damage output, range, survivability, and special effects.
Each relic comes with:
- One main perk
- Multiple side perks
- A possible full set bonus if you equip matching pieces
The real power of relics comes from understanding which perks to prioritize and which units benefit from them the most.
How to Obtain Relics
Relics are primarily obtained through Story Mode stages.
Different maps provide different relic sets, and each map has multiple difficulties:
- Easy / Normal give lower rarity relics
- Hard and Nightmare increase your chances of higher rarity relics
Higher difficulties significantly improve your odds of obtaining Epic, Legendary, and even Mythic relics. On harder modes, Mythic drop chances can climb into double digits, making Nightmare runs especially valuable for late-game players.
In addition to Story Mode relics, special relic types such as hats or boots are obtained from the Virtual Realm. Each stage in the Virtual Realm drops its own relic rewards, making it another important farming source once unlocked.
Relic Rarity and Why It Matters
Relic rarity directly affects:
- Upgrade costs
- Number of perks
- Strength of perk scaling
- Maximum upgrade level
Higher rarity relics are more expensive to enhance, but they gain significantly stronger bonuses when upgraded. Legendary and Mythic relics are the long-term investments worth building around.
Understanding Main Perks vs Side Perks
Every relic has one main perk. This is the most important stat on the relic and scales dramatically with upgrades.
Common main perks include:
- Damage
- Critical Damage
- Damage Over Time (DOT)
- Range
Main perks can roll differently on relics of the same type, meaning two chest pieces can have completely different primary stats. Because main perks scale so heavily, choosing the correct one for your unit is critical.
Side perks are secondary stats such as:
- Damage
- Critical Rate
- Range
- Resistance or efficiency-based stats
Side perks are useful, but they are not the primary reason to use a relic. The main perk should always match the role of the unit.
How Full Set Bonuses Work
Relics belong to sets. Equipping multiple pieces from the same set unlocks additional bonuses.
For example:
- 2-piece bonus might grant flat damage
- Additional bonuses may grant elemental damage or special effects
Full set bonuses only activate when the required number of pieces are equipped. If you are building around a specific unit or damage type, completing a set can provide a noticeable power spike.
However, do not force a set bonus if the main perks do not fit your unit. A strong main perk often outweighs a mediocre set bonus.
Relic Enhancement and Upgrading Explained
Relics can be enhanced using gold. Each upgrade:
- Increases the main perk significantly
- Has a chance to add new side perks
- Can upgrade existing side perks
At lower levels, upgrade success rates are high. As relics approach their maximum level, success rates drop, making upgrades more expensive and risky.
Legendary relics typically cap around level 12, while Mythic relics can reach higher levels, usually around level 15.
The scaling on main perks is extreme. For example, critical damage can jump from single-digit percentages to massive bonuses after full upgrades. This is why upgrading the right relic matters far more than upgrading many weak ones.
New Perks vs Perk Upgrades
During enhancement, two things can happen:
- A new perk is added, such as bonus range or resistance
- An existing perk is upgraded, increasing its value
New perks add flexibility, while perk upgrades strengthen what the relic already does well. Both outcomes are valuable, but upgrading a relic with the correct main perk ensures these improvements are always meaningful.
Best Practices for Using Relics Efficiently
Match main perks to unit strengths. High crit chance units benefit the most from critical damage main perks, while AoE units benefit from range or DOT-focused relics.
Do not rush upgrades early. Save gold and focus on upgrading Legendary or Mythic relics instead of spreading resources across lower rarity gear.
Experiment with combinations. Units can equip up to three relics, allowing you to mix sets or focus entirely on raw stat scaling depending on your playstyle.
Avoid upgrading relics just because they are high rarity. A poorly rolled main perk can make even a Mythic relic underwhelming.
Relics are not just small stat boosts. When fully upgraded and properly matched to a unit, they can multiply damage output, extend range dramatically, and enable powerful late-game builds. Combined with unit traits and upgrades, relics form the backbone of high-level progression.
The system is designed for experimentation, so testing different builds and setups is part of the experience. Once you understand how relics truly work, they become one of the most satisfying systems in Universal Tower Defense.