Magic Power (MP, m.p.) is also known as mana.
MP is generated and stored using your nodes.
- The efficiency at which your nodes generate mana is controlled by the % of land that nodes occuppy.
- The capacity for MP storage that your nodes provide, is 1,000 mana per node. You cannot have negative MP storage. You can have an temporarilly overfilled MP storage, e.g. when an enemy is destroying nodes - spending a turn will top-off that excess storage.
- MP is consumed by many army units and heroes, by magic (spell casting, enchantments upkeep, defense assignment), by barriers. Your status report breaks down the total upkeep.
- On most servers (except Arch and Guildwar), summoning is restricted by your m.p. income:
- when your income is negative, you cannot summon, recruit or buy more troops and your enchantments will no longer yield units, and no beneficial enchants can be cast on yourself.
- There are also game features that alter the efficiency of your nodes: when items, heroes or enchantments reduce your MP production, that is called 'Hidden upkeep'.
MP charging generates MP based on your "Income": each turn spent charging will give you an amount of mana equal to your net mana income, on top of the mana gained (Or lost) on the spent turn. So if you have nothing in your kingdom reducing mana, you will gain the net income twice, but if you are oversummoned and your mana is in negative, you will gain the net mana per charge, and have your mana reduced by the negative number as well. Thus one have to consider actual mana income when charging - when really oversummoned you gain nothing, and disbanding a bit of army before charging means you get extra mana as well.
- MP charging a good part of the turns in your turn cycle is essential for day-to-day oversummoning, and in upkeeping a huge army on relative small land, and an important part for strategies for many colors.
- MP charging for an amount of turns that would overfill your nodes, is NOT a good idea: MP charge yield is accounted for early in the order of calculations, then topped off, and after that the m.p. upkeep for the amount of turns is calculated - resulting in underfilled nodes, even though you would have charged them full if you charged turn-by-turn.
- Some unique items are charged while m.p. charging.
'Zero m.p.' is the case of fully depleting your magic power, complete stacks of m.p. consuming units may disband themselves (in random order: you may be able to keep supporting some of your smaller stacks); maintained enchantments may cancel themselves; and ultimately you may lose the barriers that you build.
Game features affecting M.P.
- Mana Crystal (lesser item) generates MP for your kingdom (random amount).
- Mana Vortex (lesser item) destroys MP in target kingdom (random amount).
- Efreeti Bottle (unique item) can refill your MP on using.
- Some Uniques reduce your nodes MP generation (e.g. hidden upkeep)
- Some Uniques boost your nodes MP generation (e.g. hidden bonus m.p.)
- The Holy Light reduces your nodes MP generation (e.g. hidden upkeep)
- Black Sabbath makes your MP generation fluctuate, but on average increases production in exchange for 666 population.
- Earthquake will destroys part of targets MP, as well as ALL of your own.
- Wish can make you lose MP (100k) or give you Efreeti Bottle which can give you MP.
- Shaman ability 'channeling' increases node MP generation. The higher the hero level, the more efficient the channeling but also the more the upkeep for the hero. As a result there is shifting a break even point where the hero's channeling produces more extra MP than its upkeep, causing it to only be paying off on big land (>5,000 acres).
- Devil Prince after Contract of Soul reduces your nodes MP generation (e.g. hidden upkeep). Devil Prince and Black Sabbath effects even out about.
- Getting favour of any god, may refill part of your MP storage
- Moon god favour and most favour increases node MP generation (by 10% resp. 20%)
- Moon god disfavour and hatred decreases node MP generation (by 10% resp. 20%)
Harvesting Mana from nodes
Effectiveness of Nodes
The graph below illustrates that the more nodes you have, the less each individual nodes generates. Above a certain value, therefore it is usually not worth building any more nodes.
- Building above 55% nodes, will make you able to store more m.p., but per turn it will lower your net m.p. generation!
- The production per turn is almost the same for having 45% or 55% nodes. The latter number enables you to store more m.p. though (after charging a lot of turns or popping the mana items).
- In other words: you can support less m.p.-eating army with 70% nodes than you can on 50% nodes.
- Mana#Mana Charging doubles the depicted values (see above)
- If having much m.p. gain for invested node land numbers is your thing, having more than 45% nodes to summon and upkeep your army is typically not worth it.
- The no-oversummoning game-change has made it favourable to drop the number of nodes for traditionally mana-heavy colors such as Verdancy, Ascendant and Phantasm magic.
- Worrying about keeping your node-number just below a whole number is only important at larger amounts of land.
- If storing as much m.p. as possible on as little land you have is your goal: building over 45% nodes is worth it.
Details in the graph
- Stepped decreasing linear lines in the graph show decreasing gain-per-node above 10% node land use (LEFT axis) for normal and moons-favour situation.
- Saw-tooth parabolic-like curves on the graph show what the m.p. yield for a given %percentage of nodes (RIGHT axis) for 2K, 3K, 4K, 5K and 5K+moon's favour situations.
Base node yield formula
After some investigation, i found out the REAL node yield formula.
Yield = XL/100 + N(100-X)/10 with X=floor(100N/L)
For full percentages this gives:
Yield Y = (10XL+100XL-X²L)/1000 = (110XL-X²L)/1000 = XL(110-X)/1000
In this formula:
- Rndd= Rounded down function
- N = amount of nodes
- L = amount of land
Example1: Land=5000, N=1000, X=20
- Yield = 20x5000/100 + 1000(80)/10 = 1000+8000 = 9000.
Example2: Land=5000, N=2000, X=40
- Yield = 40x5000/100 + 2000(60)/10 = 2000+12000 = 14000.
Example3: Land=5000, N=1990, X=39, N/L=39.8
- Yield = 39x5000/100 + 1990(61)/10 = 1950+12139 = 14089.
- Max gain is thus when the first derative of this formula is 0: (for full percentages)
- Max Yield for X: (110L-2X)/1000 = 0
- <=> 2X = 110
- <=> X = 55
- Max gain in total is thus indeed at 55.99%.
- Yield Y is your base income. It can now be influenced by:
- Alchemist : - 0.10 Y
- Moon's Favour : + 0.10Y
- Holy Grail : - 1000
- The Holy Light : - 0.25 Y
- Because of an extra rounding in the old m.p. formula, it was better to have (for example) 43.99% than to have 44.0% nodes. Depending on the number of nodes and the amount of land, destroying one could be more beneficial than building one.
- This extra rounding in the middle of the mana income formula was removed, getting rid of the local maxima and making M.P. income smoothly increase along with nodes at all points (with diminishing returns and until 55% max, as always).
UBB thread of interest: http://ubb.the-reincarnation.com/viewtopic.php?t=12718